Substrate processing apparatus

ABSTRACT

A substrate processing apparatus includes a substrate holder, a rotating mechanism, a processing liquid discharge unit, and a gas discharge unit. The processing liquid discharge unit discharges a liquid flow of a processing liquid such that the liquid flow comes into contact with a landing position in a rotation path of a peripheral portion of an upper surface of the substrate being rotated. The gas discharge unit discharges a first gas flow of an inert gas from above toward a first position upstream from the landing position in a direction of rotation of the substrate in the rotation path, and discharges a second gas flow of the inert gas from above toward a second position upstream from the first position in the direction of rotation of the substrate in the rotation path. The kinetic energy of the second gas flow is lower than the kinetic energy of the first gas flow.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a technique of processing substratessuch as a semiconductor wafer, a glass substrate for liquid crystaldisplay, a glass substrate for plasma display, a substrate for opticaldisc, a substrate for magnetic disk, a substrate for magneto-opticaldisk, a glass substrate for photomask, and a substrate for solar cell(hereinafter, merely referred to as “substrates”).

Description of the Background Art

A device pattern (circuit pattern) is not usually formed right up to theend face of a substrate, and in many cases, the device pattern is formedin the upper surface region located inside from the end face of thesubstrate by a constant width.

In the deposition step for forming a device pattern, however, a film maybe formed up to the outside of the region in which a device pattern isformed (hereinafter, merely referred to as a “device region”). The filmformed outside of the device region is not required and also can causevarious malfunctions. For example, the film formed outside of the deviceregion may peel off during the processing steps, reducing yields orcausing malfunction in, for example, a substrate processing apparatus.

In consideration of the above, the process of removing a thin filmformed outside of the device region by etching, or, so-called beveletching process is performed in some cases, and apparatuses forperforming such a process are proposed (for example, see Japanese PatentApplication Laid-Open Nos. 2011-066194 and 2009-070946).

The apparatuses of Japanese Patent Application Laid-Open Nos.2011-066194 and 2009-070946 discharge a processing liquid onto aperipheral portion of an upper surface of a substrate from nozzlesarranged above the peripheral portion while rotating the substrate aboutthe central axis in a horizontal plane, thereby processing theperipheral portion of the upper surface. The nozzles have outlets thatare opposed to a part of the rotation path of the peripheral portion ofthe substrate from above. The nozzles continuously discharge aprocessing liquid such that the processing liquid comes into contactwith the portion, which is located below the outlets, of the peripheralportion of the upper surface of the substrate being rotated. Each partof the peripheral portion of the upper surface repeatedly passes throughbelow the nozzles, and each time, is supplied with a fresh processingliquid from the nozzles.

Japanese Patent Application Laid-Open Nos. 2005-142290, 2014-072389, and2003-264168 describe the apparatuses that supply processing liquids suchas various chemical solutions to an upper surface of a substrate whileheating the substrate by a heater opposed to the substrate, therebyprocessing the substrate. Heating the substrate improves, for example, aprocessing rate.

The apparatus of Japanese Patent Application Laid-Open No. 2005-142290includes a heater opposed to the peripheral portion of the upper surfaceof the substrate and another heater opposed to the peripheral portion ofthe lower surface of the substrate. The apparatus supplies a processingliquid to the central portion of the upper surface while heating theperipheral portion of the substrate by these heaters from above andbelow, thereby processing the entire upper surface. The apparatus ofJapanese Patent Application Laid-Open No. 2014-072389 discharges aprocessing liquid onto the central portion of the upper surface of thesubstrate while heating the entire substrate by the heater opposed tothe entire lower surface of the substrate, thereby processing the entireupper surface. The apparatus of Japanese Patent Application Laid-OpenNo. 2003-264168 discharges a processing liquid onto the peripheralportion of the upper surface of the substrate while heating theperipheral portion of the substrate by an annular heater opposed to theperipheral portion of the lower surface of the substrate, therebyprocessing the peripheral portion of the upper surface.

Japanese Patent Application Laid-Open No. 2004-79908 describes asubstrate processing apparatus including an etching liquid supply nozzleand a pure water supply nozzle. The etching liquid supply nozzledischarges an etching liquid onto a plurality of positions of aperipheral portion of an upper surface of a substrate, which havedifferent distances from the center of rotation of the substrate. Thepure water supply nozzle discharges pure water for protection onto thecentral portion of the upper surface of the substrate. The pure waterdischarged onto the central portion of the upper surface is supplied tothe entire upper surface by the rotation of the substrate and washesaway the etching liquid dispersed in a to-be-protected region of theupper surface except for the peripheral portion. This protects theto-be-protected region. The etching liquid has a high concentration atthe position with which the etching liquid comes into contact, and theetching liquid that has spread from that position toward the peripheryis diluted with pure water and accordingly has a decreasedconcentration. For the etching process to advance uniformly at therespective positions with different radial distances from the center ofrotation in the peripheral portion of the substrate, the apparatus ofJapanese Patent Application Laid-Open No. 2004-79908 supplies an etchingliquid to the plurality of positions with different distances from thecenter of rotation of the substrate, to thereby make the concentrationof the etching liquid uniform in the peripheral portion of thesubstrate.

Japanese Patent Application Laid-Open No. 2003-86567 discloses asubstrate processing apparatus including an etching liquid dischargenozzle and a rinse liquid discharge nozzle. The etching liquid dischargenozzle discharges an etching liquid such that the etching liquid comesinto contact with the peripheral portion of the substrate. The rinseliquid discharge nozzle discharges a rinse liquid such that the rinseliquid comes into contact with the position of the substrate located onthe side closer to the center of the substrate than the position withwhich the etching liquid comes into contact. The apparatus firstpositions both of the nozzles such that the etching liquid and the rinseliquid come into contact with two portions of the substrate closer tothe center of the substrate, and then discharges the etching liquid andthe rinse liquid from the respective nozzles, thereby performing anetching process. Subsequently, the apparatus stops discharging theetching liquid without changing the positions of the nozzles andcontinuously discharges the rinse liquid, thereby performing a rinseprocess. Subsequently, the apparatus moves the nozzles together towardthe periphery of the substrate, thereby positioning the nozzles suchthat the rinse liquid comes into contact with the region from which thethin film has been removed by the first etching process and that theetching liquid comes into contact with the position on the side closerto the periphery of the substrate. The apparatus sequentially performsetching and rinse processes again after positioning. In the second rinseprocess, the rinse liquid comes into contact with the region from whichthe thin film has been removed. This prevents a situation in which therinse liquid comes into contact with the thin film, and metal ions ofthe thin film flow out and adheres to the peripheral portion.

In the apparatuses of Japanese Patent Application Laid-Open Nos.2011-066194 and 2009-070946, however, the respective parts of theperipheral portion of the upper surface arrive at the portion below thenozzle, with the processing liquid remaining in the respective parts.Thus, a processing liquid newly discharged from the nozzle (“freshprocessing liquid”) comes into contact with the processing liquid(“residual processing liquid”) to cause splashes. When the splashedprocessing liquid enters the device region, a defect occurs in thedevice pattern.

When an inert gas is discharged at a high flow rate onto the landingposition of the processing liquid in the peripheral portion of the uppersurface of the substrate toward the upstream portion in the direction ofrotation of the substrate, the residual processing liquid is blown offby a gas flow of an inert gas to be removed from the peripheral portion.This prevents a collision between the residual processing liquid and afresh processing liquid. If an inert gas comes into contact with theresidual processing liquid at a high flow rate, however, the residualprocessing liquid may splash to arrive at the device region.

If the flow rate of the inert gas is decreased to restrict thegeneration of splashes that can arrive at the device region, theresidual processing liquid cannot be completely removed from theperipheral portion. As a result, a fresh processing liquid may come intocontact with the residual processing liquid and cause splashes, and thesplashed processing liquid may enter the device region.

According to Japanese Patent Application Laid-Open Nos. 2005-142290,2014-072389, and 2003-264168, a space exists between the substrate andthe heater, and as the substrate rotates, the room-temperatureatmosphere existing around the peripheral portion of the substrate istaken into the space between the substrate and the heater. The substrateis cooled from the lower surface by the room-temperature atmosphere,which unfortunately decreases the heating efficiency of the substrate.

In the apparatuses of Japanese Patent Application Laid-Open Nos.2004-79908 and 2003-86567, the etching liquid discharged onto theperipheral portion of the upper surface of the substrate wraps aroundthe lower surface of the substrate. As a result, the lower surface ofthe substrate, which is not to be etched, may be etched, thus damagingthe lower surface. In addition, the pure water and the rinse liquid thatprotect a to-be-protected region of the upper surface may dilute theetching liquid, decreasing the processing efficiency.

SUMMARY OF THE INVENTION

The present invention is directed to a substrate processing apparatus.

A substrate processing apparatus according to an aspect of the presentinvention includes a substrate holder, a rotating mechanism, aprocessing liquid discharge unit, and a gas discharge unit. Thesubstrate holder is rotatably disposed about a predetermined rotationaxis and holds a substrate substantially horizontally. The rotatingmechanism rotates the substrate holder about the rotation axis. Theprocessing liquid discharge unit discharges a liquid flow of aprocessing liquid such that the liquid flow comes into contact with alanding position in a rotation path of a peripheral portion of an uppersurface of the substrate being rotated about the rotation axis. The gasdischarge unit discharges a first gas flow of an inert gas from abovetoward a first position upstream from the landing position in adirection of rotation of the substrate in the rotation path so as todirect the first gas flow from the first position toward a periphery ofthe substrate, and discharges a second gas flow of the inert gas fromabove toward a second position upstream from the first position in thedirection of rotation of the substrate in the rotation path so as todirect the second gas flow from the second position toward the peripheryof the substrate. A kinetic energy of the second gas flow when thesecond gas flow is discharged is lower than a kinetic energy of thefirst gas flow when the first gas flow is discharged.

In this apparatus, the second gas flow having kinetic energy lower thanthat of the first gas flow comes into contact with the liquid film ofthe residual processing liquid in the peripheral portion of thesubstrate at the second position. This drains out the residualprocessing liquid out of the substrate while restricting the generationof splashes of the residual processing liquid that can arrive at thedevice region, thereby reducing the film thickness of the residualprocessing liquid. Thus, the first gas flow having high kinetic energyis caused to come into contact with the thinner portion of the residualprocessing liquid at the first position on the downstream side, thusdraining most of the residual processing liquid out of the substratewhile suppressing the generation of splashes of the residual processingliquid that can arrive at the device region. This restricts thegeneration of splashes that can arrive at the device region of thesubstrate due to a collision between the residual processing liquid anda fresh processing liquid discharged onto a further downstream landingposition. Therefore, the peripheral portion of the upper surface of thesubstrate is processed while restricting the processing liquid fromentering the device region of the upper surface of the substrate.

A substrate processing apparatus according to another aspect of thepresent invention includes a substrate holder, a rotating mechanism, achemical solution discharge unit, a heater, and a gas dischargemechanism. The substrate holder is rotatably disposed about apredetermined rotation axis and holds a substrate substantiallyhorizontally. The rotating mechanism rotates the substrate holder aboutthe rotation axis. The chemical solution discharge unit discharges achemical solution onto a to-be-processed surface of the substrate. Theheater includes an opposed surface opposed to an opposite surface of thesubstrate opposite to the to-be-processed surface in a contactlessmanner, and heats the substrate. The gas discharge mechanism dischargesan inert gas preheated into a space between the opposite surface of thesubstrate and the opposed surface of the heater.

This apparatus discharges an inert gas preheated into the space betweenthe surface of the substrate opposite to the to-be-processed surface andthe opposed surface of the heater. This restricts an atmosphere fromentering the space to restrict a reduction in heating efficiency andrestricts a reduction in heating efficiency also by the inert gas.Therefore, the substrate is processed while heating the substrateefficiently.

A substrate processing apparatus according to still another aspect ofthe present invention includes a substrate holder, a rotating mechanism,a chemical solution discharge nozzle, and a rinse liquid dischargenozzle. The substrate holder is rotatably disposed about a predeterminedrotation axis and holds a substrate substantially horizontally. Therotating mechanism rotates the substrate holder about the rotation axis.The chemical solution discharge nozzle discharges a chemical solutionsuch that the chemical solution comes into contact with a first positionin a first rotation path of a peripheral portion of a to-be-processedsurface of the substrate. The rinse liquid discharge nozzle discharges arinse liquid such that the rinse liquid comes into contact with a secondposition in a second rotation path of a peripheral portion of ato-be-protected surface of the substrate opposite to the to-be-processedsurface. The second position is a position upstream from the firstposition in a direction of rotation of the substrate and is set inadvance such that, before the rinse liquid moves in a circumferentialdirection of the substrate and arrives at the first position or itsvicinity, the rinse liquid has wrapped around an end face of thesubstrate from the to-be-protected surface of the substrate and hardlywrapped around the peripheral portion of the to-be-processed surface.

This apparatus restricts the rinse liquid from wrapping around theto-be-processed surface while the rinse liquid moves from the secondposition to the first position or its vicinity in the circumferentialdirection of the substrate. This restricts the dilution of the chemicalsolution discharged onto the first position with the rinse liquid at theperipheral portion of the to-be-processed surface of the substrate. Inaddition, the rinse liquid has wrapped around the end face from theto-be-protected surface before the rinse liquid arrives at the firstposition or its vicinity in the circumferential direction of thesubstrate. As a result, the chemical solution that begins to wrap aroundthe to-be-protected surface from the first position is washed away withthe rinse liquid, thus diluting the chemical solution. This restrictsthe to-be-protected surface from being processed with the chemicalsolution that has wrapped around the to-be-protected surface whiledischarging the chemical solution onto the peripheral portion of theto-be-processed surface of the substrate to process the peripheralportion efficiently.

The present invention therefore has an object to provide a technique ofprocessing a peripheral portion of an upper surface of a substrate whilerestricting a processing liquid from entering a device region of theupper surface of the substrate. The present invention has another objectto provide a technique of processing a substrate while efficientlyheating the substrate. The present invention has sill has another objectto provide a technique of restricting a to-be-protected surface of asubstrate from being processed with a chemical solution that has wrappedaround the to-be-protected surface while efficiently discharging achemical solution onto a peripheral portion of the to-be-processedsurface to process the peripheral portion.

In the present invention, the term “to-be-processed surface” means asurface that is to be processed (“surface to be processed”), and theterm “to-be-protected surface” means a surface that is to be protected(“surface to be protected”). In the event that the processing with aprocessing liquid is to be performed on a major surface of a substrate,the major surface represents the “to-be-processed surface” of theinvention, and the surface opposite to the major surface represents the“to-be-protected surface” of the invention. Similarly, the term“to-be-processed region” means a region that is to be processed (“regionto be processed”), and the term “to-be-protected region” means a regionthat is to be protected (“region to be protected”).

These and other objects, features, aspects and advantages of the presentinvention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view for explaining the configuration of asubstrate processing apparatus according to a first embodiment of thepresent invention;

FIG. 2 is a schematic top view for explaining the configuration of thesubstrate processing apparatus according to the first (second)embodiment of the present invention;

FIG. 3 is a schematic perspective view for explaining the configurationof the substrate processing apparatus according to the first (second)embodiment of the present invention;

FIG. 4 is a top view schematically illustrating positions, at which aliquid flow of a processing liquid and gas flows of an inert gas thatare discharged from the substrate processing apparatus according to thefirst (second) embodiment of the present invention come into contactwith a peripheral portion of a substrate;

FIG. 5 is a schematic side view for explaining angles of dip of the gasflows and the liquid flow;

FIG. 6 is a schematic top view for explaining angles of traverse of thegas flows and the liquid flow;

FIG. 7 illustrates an example of how the gas flows and the liquid floware discharged;

FIG. 8 illustrates another example of how the gas flows and the liquidflow are discharged;

FIG. 9 is a perspective view of an example of nozzles of a gas dischargemechanism for peripheral portion;

FIG. 10 schematically illustrates positions at which the gas flowsdischarged from the nozzles of FIG. 9 come into contact with thesubstrate;

FIG. 11 is a perspective view of another example of nozzles of the gasdischarge mechanism for peripheral portion;

FIG. 12 schematically illustrates positions at which the gas flowsdischarged from the nozzle of FIG. 11 come into contact with thesubstrate;

FIG. 13 is a flowchart illustrating an example of the operation of thesubstrate processing apparatus of FIG. 1;

FIG. 14 is a schematic side view for explaining the configuration of thesubstrate processing apparatus according to the second embodiment of thepresent invention;

FIGS. 15 to 17 are schematic top views of a heater of FIG. 14;

FIG. 18 is a schematic cross-sectional view of a heater of the substrateprocessing apparatus according to the second (third) embodiment of thepresent invention;

FIG. 19 is a schematic cross-sectional view of the heater of FIG. 18;

FIG. 20 illustrates an example inert gas discharged between the heaterof FIG. 18 and the substrate;

FIG. 21 graphically illustrates an example relationship between a flowrate of an inert gas and a temperature of a peripheral portion of thesubstrate;

FIG. 22 is a flowchart illustrating an example operation of thesubstrate processing apparatus of FIG. 14;

FIG. 23 is a schematic side view for explaining the configuration of thesubstrate processing apparatus according to the third embodiment of thepresent invention;

FIG. 24 is a schematic top view for explaining the configuration of thesubstrate processing apparatus of FIG. 23;

FIG. 25 is a schematic perspective view for explaining the configurationof the substrate processing apparatus of FIG. 23;

FIG. 26 is a top view schematically illustrating positions at which aprocessing liquid, a rinse liquid, and an inert gas discharged by thesubstrate processing apparatus of FIG. 23 come into contact with theperipheral portion of a substrate;

FIG. 27 is a schematic side view illustrating a state in which thenozzles individually discharge the processing liquid and the like to thepositions of FIG. 26;

FIGS. 28 to 30 are schematic top views of a heater of the substrateprocessing apparatus of FIG. 23;

FIG. 31 is a flowchart illustrating an example operation of thesubstrate processing apparatus of FIG. 23;

FIG. 32 is a schematic perspective view of another example of the heaterof FIG. 28;

FIG. 33 is a schematic perspective view of another example of the heaterof FIG. 28; and

FIG. 34 is a cross-sectional view of a substrate, which schematicallyillustrates how the rinse liquid discharged by the substrate processingapparatus of FIG. 23 wraps around an end face of the substrate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described withreference to the drawings. In the drawings, components having similarconfiguration and functions bear the same reference signs, anddescription thereof will not be repeated below. The embodiments beloware examples of the implementation of the present invention, which donot limit the technical scope of the present invention. In the drawingsbelow, for easy understanding, the dimensions and the numbers of therespective portions may be exaggerated or simplified. The up and downdirection is a vertical direction, and a side close to a substraterelative to a spin chuck is an upper side. A “processing liquid”includes a “chemical solution” for use in the chemical solution processand a “rinse liquid (also referred to as a “cleaning liquid”) for use inthe rinse process of washing away the chemical solution. The substrate Whas an approximately circular surface shape. The substrate istransferred to and from the substrate processing apparatus by, forexample, a robot, with the nozzle head and the like arranged at retreatpositions. The substrate transferred to the substrate processingapparatus is detachably held by the spin chuck. The “inert gas” is a gasthat is poorly reactive to a material for the substrate W and a thinfilm formed on the surface of the substrate W, which is, for example,nitrogen (N₂) gas, argon gas, or helium gas.

1. First Embodiment

1.1. Configuration of Substrate Processing Apparatus 1

The configuration of a substrate processing apparatus 1 will bedescribed with reference to FIGS. 1 to 4. FIGS. 1 to 3 are views forexplaining the configuration of the substrate processing apparatus 1according to an embodiment. FIGS. 1 and 2 are a schematic side view anda schematic top view, respectively, of the substrate processingapparatus 1. FIG. 3 is a schematic perspective view of the substrateprocessing apparatus 1 as viewed from diagonally above. FIG. 4 is aschematic top view of a substrate W, which illustrates an example of apositional relationship among positions at which a liquid flow of aprocessing liquid and gas flows of an inert gas that are discharged fromthe substrate processing apparatus 1 come into contact with theperiphery of the substrate W.

FIGS. 1 to 3 illustrate the state in which the substrate W is beingrotated in a predetermined direction of rotation (the direction of anarrow AR1) about a rotation axis a1 by a spin chuck 21, with nozzleheads 48 to 50 arranged at their respective processing positions. InFIG. 2, the nozzle heads 48 to 50 arranged at their retreat positionsand the like are indicated by phantom lines. FIGS. 2 and 3 do notillustrate partial components of the substrate processing apparatus 1,such as a scatter prevention unit 3.

The substrate processing apparatus 1 includes a rotary holding mechanism2, the scatter prevention unit 3, a surface protection unit 4, aprocessing unit 5, a nozzle moving mechanism 6, a heating mechanism 7,and a control unit 130. These units 2 to 7 are electrically connected tothe control unit 130 and operate in response to instructions from thecontrol unit 130. The control unit 130 may be, for example, ageneral-purpose computer. In other words, for example, the control unit130 includes a CPU configured to perform various computations, a ROMthat is a read-only memory configured to store a basic program, a RAMthat is a random access memory for storing a various types ofinformation, a magnetic disk for storing, for example, control softwareand data. The control unit 130 causes a CPU that is a main control unitto perform computations in accordance with the procedure described inthe program, thereby controlling the respective units of the substrateprocessing apparatus 1.

Rotary Holding Mechanism 2

The rotary holding mechanism 2 is a mechanism that can rotate thesubstrate W while keeping the substrate W in a substantially horizontalposition, with one major surface of the substrate W facing upward. Therotary holding mechanism 2 rotates the substrate W about the rotationaxis a1 that extends vertically and passes through a center cl of themajor surface.

The rotary holding mechanism 2 includes a spin chuck (“holding member”or “substrate holder”) 21 that is a disc-shaped member smaller than thesubstrate W. The spin chuck 21 is provided such that its upper surfaceis substantially horizontal and its central axis coincides with therotation axis al. The lower surface of the spin chuck 21 is coupled witha cylindrical rotary shaft 22. The rotary shaft 22 is positioned suchthat its axis line coincides with the vertical direction. The axis lineof the rotary shaft 22 coincides with the rotation axis al. The rotaryshaft 22 is connected with a rotational drive (e.g., motor) 23. Therotational drive 23 rotatively drives the rotary shaft 22 about the axisline of the rotary shaft 22. The spin chuck 21 can accordingly rotateabout the rotation axis a1 together with the rotary shaft 22. Therotational drive 23 and the rotary shaft 22 serve as a rotatingmechanism 231 that rotates the spin chuck 21 about the rotation axis al.The rotary shaft 22 and the rotational drive 23 are accommodated in atubular casing 24.

A through hole (not shown) is provided in the central portion of thespin chuck 21 and is in communication with the interior space of therotary shaft 22. The interior space is connected with a pump (not shown)through a pipe (not shown) and an on/off valve (not shown). The pump andthe on/off valve are electrically connected to the control unit 130. Thecontrol unit 130 controls the operations of the pump and the on/offvalve. The pump can selectively supply a negative pressure and apositive pressure in accordance with the control of the control unit130. When the pump supplies a negative pressure with the substrate Wpositioned substantially horizontally on the upper surface of the spinchuck 21, the spin chuck 21 adheres to and holds the substrate W frombelow. When the pump supplies a positive pressure, the substrate W canbe removed from the upper surface of the spin chuck 21.

In this configuration, when the rotational drive 23 rotates the rotaryshaft 22 with the spin chuck 21 adhering to and holding the substrate W,the spin chuck 21 is rotated about the axis line extending vertically.This causes the substrate W held on the spin chuck 21 to rotate in thedirection of the arrow AR1 about the rotation axis a1 that extendsvertically and passes through the center c1 in the plane of thesubstrate W.

The spin chuck 21 may include a plurality of (e.g., six) chuck pinsprovided at appropriate intervals near the peripheral portion of theupper surface thereof and hold the substrate W by the plurality of chuckpins. In this case, the spin chuck 21 has a disc shape slightly largerthan the substrate W. The plurality of chuck pins detachably hold thesubstrate W such that the center c1 of the major surface of thesubstrate W coincides with the rotation axis a1 and that the substrate Wis positioned substantially horizontally at a position slightly higherthan the upper surface of the spin chuck 21. The direction of each chuckpin is selectively set, by the motor or the like electrically connectedto the control unit 130, to the direction in which the chuck pins abutagainst the periphery of the substrate W and holds the substrate W orthe direction in which the check pins depart from the periphery of thesubstrate W and release the substrate W.

Scatter Prevention Unit 3

The scatter prevention unit 3 catches, for example, a processing liquidscattered from the substrate W rotated together with the spin chuck 21.

The scatter prevention unit 3 includes a splash guard 31. The splashguard 31 is a tubular member with an open upper end and is provided soas to surround the rotary holding mechanism 2. In this embodiment, forexample, the splash guard 31 includes three members: a bottom member311, an inside member (also referred to as an “inside guard” or merely a“guard”) 312, and an outside member (also referred to as an “outsideguard”) 313. No outside member 313 may be provided, or a guard may beadditionally provided outside of the outside member 313 so as tosurround the rotary holding mechanism 2.

The bottom member 311 is a tubular member having an open upper end andincludes an annular bottom portion, a cylindrical inside wall portionextending upward from the inner edge portion of the bottom portion, anda cylindrical outside wall portion extending upward from the outer edgeportion of the bottom portion. At least an edge of the inside wallportion and its vicinity are accommodated in an inside space of aflanged member 241 provided to the casing 24 of the rotary holdingmechanism 2.

On the bottom portion is formed a drain groove (not shown) communicatingwith the space between the inside wall portion and the outside wallportion. The drain groove is connected to the drain line of a factory.The drain groove is connected with a drain mechanism that forciblyexhausts air from the groove to provide a negative state in the spacebetween the inside wall portion and the outside wall portion. The spacebetween the inside wall portion and the outside wall portion is a spacefor collecting and exhausting the processing liquid used for processingthe substrate W, and the processing liquid collected in this space isexhausted through the drain groove.

The inside member 312 is a tubular member with an open upper end, andthe upper portion (“upper-end side portion” or “upper-end portion”) ofthe inside member 312 extends inwardly and upwardly. Specifically, theupper portion extends diagonally upward toward the rotation axis al. Atthe lower portion of the inside member 312 are formed a tubular insideperipheral wall portion extending downward along the inner peripheralsurface of the upper portion and a tubular outside peripheral wallportion extending downward along the outer peripheral surface of theupper portion. With the bottom member 311 and the inside member 312close to each other, the outside wall portion of the bottom member 311is accommodated between the inside peripheral wall portion and theoutside peripheral wall portion of the inside member 312. The processingliquid or the like caught by the upper portion of the inside member 312is drained through the bottom member 311.

The outside member 313 is a tubular member with an open upper end and isprovided outside of the inside member 312. The upper portion (“upper-endside portion” or “upper-end portion”) of the outside member 313 extendsinwardly and upwardly. Specifically, the upper portion extendsdiagonally upward toward the rotation axis a1. The lower portion extendsdownward along the outside peripheral wall portion of the inside member312. The processing liquid or the like caught by the upper portion ofthe outside member 313 is drained from a gap between the outsideperipheral wall portion of the inside member 312 and the lower portionof the outside member 313.

The splash guard 31 is provided with a guard drive mechanism (“elevationdrive”) 32 that moves the splash guard 31 upward or downward. The guarddrive mechanism 32 is configured of, for example, a stepping motor. Inthis embodiment, the guard drive mechanism 32 independently moves thethree members 311, 312, and 313 of the splash guard 31 upward ordownward.

The inside member 312 and the outside member 313 are individually movedbetween their upper positions and lower positions through driving of theguard drive mechanism 32. Herein, the respective upper positions of themembers 312 and 313 are positions at which the upper edge portions ofthe 312 and 313 are arranged lateral to and above the substrate W heldon the spin chuck 21. On the other hand, the respective lower positionsof the members 312 and 313 are positions at which the upper edgeportions of the members 312 and 313 are arranged below the upper surfaceof the spin chuck 21. The upper position (lower position) of the outsidemember 313 is located slightly above the upper position (lower position)of the inside member 312. The inside member 312 and the outside member313 are moved upward or downward simultaneously or successively so asnot to come into contact with each other. The bottom member 311 isdriven by the guard drive mechanism 32 between a position at which theinside wall portion of the bottom member 311 is accommodated in theinside space of the flanged member 241 provided to the casing 24 and aposition below the above-mentioned position. It should be noted that theguard drive mechanism 32 is electrically connected to the control unit130 and operates under the control of the control unit 130. That is tosay, the position of the splash guard 31 (specifically, the respectivepositions of the bottom member 311, the inside member 312, and theoutside member 313) is controlled by the control unit 130.

Surface Protection Unit 4

The surface protection unit 4 includes a gas discharge mechanism (alsoreferred to as a “gas discharge mechanism for peripheral portion” or a“gas discharge unit”) 440 that discharges gas flows of an inert gas suchthat the gas flows come into contact with the peripheral portion of theupper surface of the substrate W held and being rotated on the spinchuck 21. The gas discharge mechanism 440 includes gas dischargemechanisms 441 and 442. The gas discharge mechanisms 441 and 442discharge an inert gas as, for example, gas-column-shaped gas flows G1and G2. The gas discharge mechanism 442 discharges the gas flow G2 ofthe inert gas such that the gas flow G2 comes into contact with aposition (“second position”) P2 upstream from a position (“firstposition”) P1, at which the gas flow G1 discharged from the gasdischarge mechanism 441 comes into contact with the peripheral portionof the substrate W, in the direction of rotation of the substrate W.

The surface protection unit 4 further includes a gas discharge mechanism(also referred to as a “gas discharge mechanism for central portion” or“another gas discharge unit”) 443 that discharges a gas flow G3 of theinert gas onto the center or its vicinity of the upper surface of thesubstrate W held and being rotated on the spin chuck 21. The surfaceprotection unit 4 discharges the gas flows G1 to G3 of the inert gasonto the upper surface of the substrate W respectively from the gasdischarge mechanisms 441 to 443, thereby protecting a to-be-protectedregion (“device region”) S4 (FIG. 4) of the upper surface of thesubstrate W from, for example, the processing liquid discharged so as tocome into contact with an annular processing region S3 (FIG. 4) definedby the peripheral portion of the upper surface of the substrate W. Theto-be-protected region S4 is a region of the upper surface of thesubstrate W except for the processing region S3.

The gas discharge mechanism 440 includes a nozzle head 48. The gasdischarge mechanism 443 includes a nozzle head 49. The nozzle heads 48and 49 are attached to the distal ends of elongated arms 61 and 62 ofthe nozzle moving mechanism 6 described below. The arms 61 and 62 extendalong the horizontal plane. The nozzle moving mechanism 6 moves the arms61 and 62 respectively to move the nozzle heads 48 and 49 between theirprocessing positions and retreat positions.

The nozzle head 48 includes nozzles 41 and 42 and a holding memberholding these nozzles. The holding member is formed of, for example, aplate-shaped member extending along the horizontal plane and aprotruding member protruding upward from one end of the plate-shapedmember, which are bonded together, and has an L-shaped cross-sectionalshape. The protruding member has a distal end attached to the distal endof the arm 61 and protrudes more in the extension direction of the arm61 than the proximal end of the arm 61 relative to the distal end of thearm 61. The nozzles 41 and 42 are held by the plate-shaped member whilepassing through the plate-shaped member vertically. The nozzles 41 and42 each have a distal end portion (lower end portion) protrudingdownward from the lower surface of the plate-shaped member and an upperend portion protruding upward from the upper surface of the plate-shapedmember. The upper ends of the nozzles 41 and 42 are connectedrespectively with first ends of pipes 471 and 472. Second ends of pipes471 and 472 are connected respectively to gas supply sources 451 and452. At some midpoint in the pipe 471, a flow rate controller 481 and anon/off valve 461 are provided sequentially from the gas supply source451 side; at some midpoint in the pipe 472, a flow rate controller 482and an on/off valve 462 are provided sequentially from the gas supplysource 452 side.

When the nozzle moving mechanism 6 arranges the nozzle head 48 at itsprocessing position, the outlet of the nozzle 41 is opposed to a part ofa rotation path of the peripheral portion of the substrate W rotated bythe rotary holding mechanism 2, and the outlet of the nozzle 42 isopposed to another part of the rotation path.

With the nozzle head 48 arranged at the processing position, the nozzles41 and 42 are supplied with an inert gas (in the illustrated example,nitrogen (N₂) gas) respectively from the gas supply sources 451 and 452.The nozzle 41 discharges the gas flow G1 of the supplied inert gas fromabove such that the gas flow G2 comes into contact with the position P1defined in the rotation path of the peripheral portion of the substrateW. The nozzle 41 discharges the gas flow G1 in a predetermined directionthrough the outlet such that the discharged gas flow G1 arrives at theposition P1 and then flows from the position P1 toward the periphery ofthe substrate W. The nozzle 42 discharges the gas flow G2 of thesupplied inert gas from above such that the gas flow G2 comes intocontact with the position P2 (“second position”) (FIG. 4) defined in therotation path. The nozzle 42 discharges the gas flow G2 in apredetermined direction through the outlet such that the discharged gasflow G2 arrives at the position P2 and then flows from the position P2toward the periphery of the substrate W.

The substrate W has a radius of, for example, 150 mm. The “peripheralportion” of the substrate W is an annular portion with a width D2 fromthe periphery of the substrate W. The width D2 of the peripheral portionis, for example, 3 to 30 mm. The processing region S3 is an annularportion with a width D3 from the periphery of the substrate W. The widthD3 of the processing region S3 is, for example, 1 to 5 mm. Theprocessing region S3 is a partial periphery-side region of theperipheral portion of the to-be-processed surface of the substrate W.

A liquid flow L1 of a processing liquid discharged from a nozzle head 50of the processing unit 5, which will be described below, comes intocontact with a position (“landing position”) PL1 (FIG. 4) defined in therotation path of the peripheral portion on the upper surface of thesubstrate W. A width D1 of the liquid flow L1 in the radial direction ofthe substrate W is, for example, 0.5 to 2.5 mm. The nozzle head 50 canselectively discharge the liquid flow L1 of the processing liquid fromeach of a plurality of nozzles 51 a to 51 d. The position PL1 slightlyvaries depending on the arrangements of the nozzles 51 a to 51 d and thedirection in which the processing liquid is discharged. The position P1is located upstream from the position PL1 corresponding to any of thenozzles 51 a to 51 d in the direction of rotation of the substrate Walong the circumferential direction of the substrate W. The position P2is located upstream from the position P1 in the direction of rotation ofthe substrate W along the circumferential direction of the substrate W.

That is to say, the gas discharge mechanism 440 discharges the gas flow(“first gas flow”) G1 of the inert gas from above toward the position P1upstream from the position PL1, with which the processing liquiddischarged from the processing unit 5 comes into contact, in thedirection of rotation of the substrate W along the circumferentialdirection of the substrate W in the rotation path of the peripheralportion of the substrate W. The gas discharge mechanism 440 dischargesthe gas flow G1 in a predetermined direction such that the dischargedgas flow G1 flows from the position P1 toward the periphery of thesubstrate W. Also, the gas discharge mechanism 440 discharges the gasflow (“second gas flow”) G2 of the inert gas from above toward theposition P2 upstream from the position P1 in the direction of rotationof the substrate W along the circumferential direction of the substrateW in the rotation path. The gas discharge mechanism 440 discharges thegas flow G2 in a predetermined direction such that the discharged gasflow G2 flows from the position P2 toward the periphery of the substrateW.

The nozzle head 49 of the gas discharge mechanism 443 includes acolumnar member 93 attached to the lower surface of the distal endportion of the arm 62, a disc-shaped shielding plate 90 attached to thelower surface of the columnar member 93, and a cylindrical nozzle 43.The axis line of the columnar member 93 coincides with the axis line ofthe shielding plate 90, and each axis line extends vertically. The lowersurface of the shielding plate 90 extends along the horizontal plane.The nozzle 43 passes through the columnar member 93 and the shieldingplate 90 vertically such that the axis line of the nozzle 43 coincideswith the axis lines of the shielding plate 90 and the columnar member93. The upper end of the nozzle 43 further passes through the distal endportion of the arm 62 to be open to the upper surface of the arm 62. Theupper opening of the nozzle 43 is connected with a first end of the pipe473. A second end of the pipe 473 is connected to the gas supply source453. At some midpoint in the pipe 473 are provided a flow ratecontroller 483 and an on/off valve 463 sequentially from the gas supplysource 453 side. The lower end of the nozzle 43 is open to the lowersurface of the shielding plate 90. The opening is an outlet of thenozzle 43.

When the nozzle moving mechanism 6 arranges the nozzle head 49 at itsprocessing position, the outlet of the nozzle 43 is opposed to thecenter and its vicinity of the upper surface of the substrate W. In thisstate, the nozzle 43 is supplied with an inert gas (in the illustratedexample, nitrogen (N₂) gas) from the gas supply source 453 through thepipe 473. The nozzle 43 discharges the supplied inert gas as a gas flowG3 of the inert gas onto the center or its vicinity of the upper surfaceof the substrate W. The gas flow G3 spreads radially toward theperiphery of the substrate W from above the central portion of thesubstrate W. Specifically, the gas discharge mechanism 443 discharges aninert gas from above the central portion of the upper surface of thesubstrate W to generate a gas flow spreading toward the periphery of thesubstrate W from above the central portion.

Each of the flow rate controllers 481 to 483 includes a flowmeter thatdetects a flow rate of a gas flowing through each of the pipes 471 to473 in which the flow rate control unit is provided and a variable valvethat can adjust the flow rate of the gas. The control unit 130 controlsan open/close amount of the variable valve of each of the flow ratecontrollers 481 to 483 via a valve control mechanism (not shown) suchthat a flow rate detected by the flowmeter is equal to a target flowrate for each of the flow rate controllers 481 to 483. The control unit130 can set a target flow rate within a predetermined range inaccordance with the preset setup information to freely control a flowrate of a gas passing through each of the flow rate controllers 481 to483 in a predetermined range. The control unit 130 also controls theon/off valves 461 to 463 between the open state and the closed state viathe valve control mechanisms. The control unit 130 thus controls how thegas flows G1 to G3 are discharged from the nozzles 41 to 43 (such as adischarge start timing, a discharge end timing, and a discharge flowrate).

How easily the residual processing liquid is blown off by the gas flowsG1 and G2 varies depending on the film quality of the surface of thesubstrate W. Of the hydrophobic film quality and the hydrophilic filmquality, the hydrophobic film quality is less likely to blow off theresidual processing liquid, and the hydrophilic film quality is morelikely to blow off the residual processing liquid. Therefore, how thegas flow G1 is discharged is preferably set in accordance with the filmquality of the surface of the substrate W.

Processing Unit 5

The processing unit 5 processes the processing region S3 in theperipheral portion of the upper surface of the substrate W held on thespin chuck 21. Specifically, the processing unit 5 supplies theprocessing liquid to the processing region S3 of the substrate W held onthe spin chuck 21.

The processing unit 5 includes a processing liquid discharge mechanism830. The processing liquid discharge mechanism 830 discharges the liquidflow L1 of the processing liquid such that the liquid flow L1 comes intocontact with a part of the peripheral portion (more specifically, theprocessing region S3 of the peripheral portion) of the upper surface(to-be-processed surface) of the substrate W held and being rotated onthe spin chuck 21. The liquid flow L1 is discharged so as to come intocontact with the position PL1 in the rotation path of the peripheralportion of the upper surface (more specifically, the processing regionS3). The liquid flow L1 has a liquid columnar shape. The processingliquid discharge mechanism 830 includes the nozzle head 50. The nozzlehead 50 is attached to the distal end of an elongated arm 63 of thenozzle moving mechanism 6. The arm 63 extends along the horizontalplane. The nozzle moving mechanism 6 moves the arm 63 to move the nozzlehead 50 between its processing position and its retreat position.

The nozzle head 50 includes nozzles 51 a to 51 d and a holding memberholding these nozzles. The holding member includes, for example, aplate-shaped member extending along the horizontal plane and aprotruding member protruding upward from one end of the plate-shapedmember, which are bonded together, and has an L-shaped cross-sectionalshape. The distal end of the protruding member is attached to the distalend of the arm 63, and the plate-shaped member protrudes further in theextension direction of the arm 63 beyond the proximal end of the arm 63relative to the distal end of the arm 63. The nozzles 51 a to 51 d arearranged in line along the extension direction of the arm 63 in orderfrom the distal end side of the plate-shaped member. The nozzles 51 a to51 d are held by the plate-shaped member while passing through theplate-shaped member vertically. The distal end portions (lower endportions) of the nozzles 51 a to 51 d protrude downward from the lowersurface of the plate-shaped member, each of which includes an outlet atits distal end. The proximal end portions (upper end portions) of thenozzles 51 a to 51 d protrude upward from the upper surface of theplate-shaped member.

The nozzles 51 a to 51 d are connected with a processing liquid supplyunit 83 that is a pipe system that supplies the processing liquid tothese nozzles. Specifically, the upper ends of the nozzles 51 a to 51 dare connected with first ends of pipes 832 a to 832 d of the processingliquid supply unit 83. Each of the nozzles 51 a to 51 d is supplied withthe processing liquid from the processing liquid supply unit 83 anddischarges the supplied processing liquid through the outlet at itsdistal end. The processing liquid discharge mechanism 830 discharges theliquid flow L1 of the processing liquid in accordance with the controlof the control unit 130 from one nozzle, which is determined by thecontrol information set by the control unit 130, among the nozzles 51 ato 51 d. In the illustrated example, the liquid flow L1 of theprocessing liquid is discharged from the nozzle 51 c.

Specifically, the processing liquid supply unit 83 is configured as acombination of an SC-1 supply source 831 a, a DHF supply source 831 b,an SC-2 supply source 831 c, a rinse liquid supply source 831 d, aplurality of pipes 832 a to 832 d, and a plurality of on/off valves 833a to 833 d. SC-1, DHF, and SC-2 represent chemical solutions. Theprocessing liquid discharge mechanism 830 is thus a chemical solutiondischarge unit that discharges the chemical solution onto the peripheralportion of the substrate W.

The SC-1 supply source 831 a is a supply source that supplies SC-1. TheSC-1 supply source 831 a is connected to the nozzle 51 a through thepipe 832 a in which the on/off valve 833 a is interposed. When theon/off valve 833 a is opened, thus, the SC-1 supplied from the SC-1supply source 831 a is discharged from the nozzle 51 a.

The DHF supply source 831 b is a supply source that supplies DHF. TheDHF supply source 831 b is connected to the nozzle 51 b through the pipe832 b in which the on/off valve 833 b is interposed. When the on/offvalve 833 b is opened, thus, the DHF supplied from the DHF supply source831 b is discharged from the nozzle 51 b.

The SC-2 supply source 831 c is a supply source that supplies SC-2. TheSC-2 supply source 831 c is connected to the nozzle 51 c through thepipe 832 c in which the on/off valve 833 c is interposed. When theon/off valve 833 c is opened, thus, the SC-2 supplied from the SC-2supply source 831 c is discharged from the nozzle 51 c.

The rinse liquid supply source 831 d is a supply source that supplies arinse liquid. Herein, the rinse liquid supply source 831 d supplies, forexample, pure water as the rinse liquid. The rinse liquid supply source831 d is connected to the nozzle 51 d through the pipe 832 d in whichthe on/off valve 833 d is interposed. When the on/off valve 833 d isopened, thus, the rinse liquid supplied from the rinse liquid supplysource 831 d is discharged from the nozzle 51 d. The rinse liquid maybe, for example, pure water, hot water, ozone water, magnetic water,regenerated water (hydrogen water), various organic solvents (e.g., ionwater, isopropyl alcohol, or, IPA, and functional water such as CO₂water). The nozzles 51 a, 51 b, and 51 c that respectively dischargeSC-1, DHF, and SC-2 are also referred to as “processing liquid dischargenozzles” or “chemical solution discharge nozzles”.

The processing liquid supply unit 83 selectively supplies SC-1, DHF,SC-2, and a rinse liquid. When the processing liquid supply unit 83supplies the processing liquid (SC-1, DHF, SC-2, or rinse liquid) from acorresponding nozzle among the nozzles 51 a to 51 d, the nozzledischarges the liquid flow L1 of the processing liquid such that theliquid flow L1 comes into contact with the processing region S3 of theperipheral portion of the upper surface of the substrate W beingrotated. It should be noted that each of the on/off valves 833 a to 833d of the processing liquid supply unit 83 is opened or closed under thecontrol of the control unit 130 by a valve open/close mechanism (notshown) electrically connected to the control unit 130. That is to say,the control unit 130 controls how the processing liquid is dischargedfrom the nozzles of the nozzle head 50 (such as a type of the processingliquid, a discharge start timing, a discharge end timing, and adischarge flow rate). In other words, the processing liquid dischargemechanism 830 discharges, through the control of the control unit 130,the liquid flow L1 of the processing liquid such that the liquid flow L1comes into contact with the position PL1 in the rotation path of theperipheral portion of the upper surface of the substrate W being rotatedabout the rotation axis a1.

Nozzle Moving Mechanism 6

The nozzle moving mechanism 6 is a mechanism that moves the nozzle heads48 to 50 of the gas discharge mechanisms 440 and 443 and the processingliquid discharge mechanism 830 between their respective processingpositions and retreat positions. The nozzle moving mechanism 6 includesthe arms 61 to 63 extending horizontally, nozzle bases 64 to 66, anddrives 67 to 69. The nozzle heads 48 to 50 are respectively attached tothe distal end portions of the arms 61 to 63.

The proximal end portions of the arms 61 to 63 are connected to theupper end portions of the nozzle bases 64 to 66. The nozzle bases 64 to66 are arranged dispersedly around the casing 24, with their axis linesextending vertically. The nozzle bases 64 to 66 extend vertically alongtheir axis lines, each of which has a shaft rotatable about the axisline. The axis lines of the nozzle bases 64 to 66 coincide with the axislines of the respective shafts. The upper end portions of the nozzlebases 64 to 66 are attached to the upper end portions of the respectiveshafts. The rotations of the shafts causes the upper end portions of thenozzle bases 64 to 66 to rotate about the axis lines of the respectiveshafts, that is, the axis lines of the nozzle bases 64 to 66. The nozzlebases 64 to 66 are respectively provided with the drives 67 to 69 thatrotate their shafts about the axis lines. The drives 67 to 69 eachinclude, for example, a stepping motor.

The drives 67 to 69 respectively rotate the upper end portions of thenozzle bases 64 to 66 via the shafts of the nozzle bases 64 to 66. Alongwith the rotations of the upper end portions, the nozzle heads 48 to 50respectively rotate about the axis lines of the nozzle bases 64 to 66.This causes the drives 67 to 69 to respectively move the nozzle heads 48to 50 horizontally between their processing positions and retreatpositions.

When the nozzle head 48 is arranged at the processing position, theoutlet of the nozzle 41 is opposed to a part of the rotation path of theperipheral portion of the substrate W rotated by the rotary holdingmechanism 2, and the outlet of the nozzle 42 is opposed to another partof the rotation path.

When the nozzle head 49 is arranged at the processing position, thenozzle 43 is located above the center c1 of the substrate W, and theaxis line of the nozzle 43 coincides with the rotation axis a1 of thespin chuck 21. The outlet (lower opening) of the nozzle 43 is opposed tothe central portion of the substrate W. The lower surface of theshielding plate 90 is opposed to the upper surface of the substrate W inparallel therewith. The shielding plate 90 is close to the upper surfaceof the substrate W in a contactless manner.

When the nozzle head 50 is arranged at the processing position, thenozzles 51 a to 51 d are arranged at the processing positions. Morestrictly, for example, in the case in which the nozzles 51 a to 51 d arearranged in a line along the extension direction of the arm 63, thedistance between the nozzle 51 a and the periphery of the circularsubstrate W, the distance between the nozzle 51 b and the periphery ofthe circular substrate W, the distance between the nozzle 51 and theperiphery of the circular substrate W, and the distance between thenozzle 51 d and the periphery of the circular substrate W slightlydiffer from each other. Even when the width of the processing region S3is small, the drive 69 adjusts the processing position of the nozzlehead 50 in accordance with the nozzle that discharges the processingliquid among the nozzles 51 a to 51 d under the control of the controlunit 130 such that the processing liquids selectively discharged fromthe nozzles 51 a to 51 d come into contact with the processing regionS3.

The respective retreat positions of the nozzle heads 48 to 50 arepositions that do not interfere with the transport path of the substrateW and do not interfere with each other. Each retreat position is, forexample, a position outside of and above the splash guard 31.

The drives 67 to 69 are electrically connected to the control unit 130and operate under the control of the control unit 130. The control unit130 causes the nozzle moving mechanism 6 to arrange the nozzle heads 48and 50 at the processing positions in accordance with the preset setupinformation such that the gas flows G1 and G2 and the liquid flow L1respectively come into contact with the positions P1, P2, and PL1 in therotation path of the peripheral portion of the substrate W. Thepositions P1, P2, and PL1 are adjusted by changing the setupinformation. The control unit 130 causes the nozzle moving mechanism 6to arrange the nozzle head 49 at the processing position in accordancewith the setup information such that the gas flow G3 comes into contactwith the center of the substrate W or its vicinity. That is to say, thecontrol unit 130 controls the positions of the nozzle heads 48 to 50.Specifically, the control unit 130 controls the positions of the nozzles41 to 43 and 51 a to 51 d.

For the control of the positions P1, P2, and PL1, a central angle θ(FIG. 4) is preferably set to not greater than 180°, more preferably notgreater than 90°, and still more preferably not greater than 45°. Thecentral angle θ is formed between the line segments, namely, a linesegment connecting the center c1 of the substrate W and the position PL1that is the landing position of the processing liquid, and a linesegment connecting the center c1 and the position P2 with which the gasflow G2 comes into contact. This is because a smaller central angle θenables the residual processing liquid to stay at each portion of theprocessing region S3 of the substrate W for a longer period of time,thereby improving a processing rate.

The liquid flow L1 of the processing liquid, which has been dischargedonto the position PL1 in the rotation path of the peripheral portion ofthe upper surface of the substrate W, moves in the circumferentialdirection of the substrate W while adhering to the processing region S3in the form of a liquid film. During the movement, the central angle ofthe circular arc, which connects the portion to which the liquid film ofthe processing liquid adheres and the position PL1 along the end face ofthe substrate W, becomes greater. The centrifugal force due to therotation of the substrate W acts on the liquid film of the processingliquid during the movement. Thus, approximately 80% of the processingliquid is drained out of the substrate W until the central angle reaches90°. This rate varies depending on, for example, the rotational speedand film quality of the substrate W, and the volume and viscosity of theprocessing liquid discharged.

If the width of the processing region S3, that is, the width for whichthe etching process or any other process is intended to be performed is1 mm, the liquid flow L1 of the processing liquid is preferablydischarged so as to come into contact with a portion of the substrate Wwith a width in the range of 0.5 mm from the periphery of the substrateW. In this case, to efficiently remove the residual processing liquidfrom the substrate W while restricting splashes that arrive at theto-be-protected region S4, the gas flows G1 and G2 are preferablydischarged such that the centers of the cross-sections of the gas flowsG1 and G2 of the inert gas come into contact with the portion of thesubstrate W within the range of, for example, 4 to 8 mm from theperiphery of the substrate W. The width of the liquid film of theresidual processing liquid that adheres to the peripheral portion of thesubstrate W normally spreads to be larger than the width of the liquidflow L1 of the processing liquid that comes into contact with theposition PL1. Therefore, as described above, the widths of the gas flowsG1 and G2 of the inert gas are preferably larger than the width of theliquid flow L1 of the processing liquid that comes into contact with theperipheral portion of the substrate W. Specifically, the widths of thegas flows G1 and G2 of the inert gas are preferably set to be, forexample, three to five times the width of the liquid flow L1. Theresidual processing liquid that adheres to the peripheral portion of thesubstrate W is thus efficiently drained out of the substrate W by thegas flows G1 and G2.

Heating Mechanism 7

The heating mechanism 7 is provided below the peripheral portion of thelower surface of the substrate W. The heating mechanism 7 includes anannular heater 71 and an electric circuit (not shown) that suppliespower to the heater 71 in accordance with the control of the controlunit 130.

The heater 71 is arranged annularly around the spin chuck 21 below theperipheral portion of the lower surface so as to be opposed to theportion, with which the upper surface of the spin chuck 21 is not incontact, of the lower surface of the substrate W in a contactlessmanner. The upper surface of the heater 71 is parallel to the lowersurface of the substrate W. The heater 71 is held by a holding member(not shown) provided upright on the casing 24. The heater 71 is providedto improve the processing rate of the substrate W with the processingliquid, and heats the peripheral portion of the substrate W from itslower surface side. The heating mechanism 7 further includes a movingmechanism (not shown) such as a motor. The moving mechanism moves theheater 71 upward or downward to arrange the heater 71 at the processingposition or the retreat position below the processing position. Theretreat position is a position at which the heater 71 does not interferewith the transport path for the substrate W when the substrate W istransferred to and from the substrate processing apparatus 1. The heater71 is supplied with power while being arranged at the processingposition, and the heater 71 generates heat to heat the peripheralportion of the substrate W.

The electric circuit that supplies power to the heater 71 and the movingmechanism that moves the heater 71 upward or downward are electricallyconnected to the control unit 130, and operate under the control of thecontrol unit 130. That is to say, the control unit 130 controls how thesubstrate W is heated by the heater 71 and the position of the heater71.

1-2. Discharge Directions of Gas Flows and Liquid Flow

FIGS. 5 and 6 are a schematic side view and a schematic top view,respectively, for explaining angles of dip α1, α2, and αL and angles oftraverse β1 and β2 formed by the gas flows G1 and G2 and the liquid flowL1 discharged from the nozzles 41, 42, and 51 c of the substrateprocessing apparatus 1. FIGS. 5 and 6 illustrate the nozzles 41, 42, and51 c as a common nozzle and the gas flows G1 and G2 and the liquid flowL1 as a common flow. The term “angle of dip” refers to an angle formedby the horizontal plane and the direction in which the gas flow G1 (gasflow G2, liquid flow L1) is discharged. The angle of dip is 90° when agas flow or the like is discharged vertically downward or 0° when it isdischarged horizontally. The term “angle of traverse” refers to an angleformed by the tangent on the end face of the substrate W closest to theposition P1 (P2, PL1) at which the gas flow G1 (gas flow G2, liquid flowL1) comes into contact with the substrate W and the discharge directionin which the gas flow G1 (gas flow G2, liquid flow L1) is projected ontothe substrate W. The angle of traverse is 0° when the dischargedirection in the projection extends along the tangential direction or90° when it extends along the radial direction of the substrate W.

The angles of dip α1 and α2 of the gas flows G1 and G2 are set withinthe range of 45° to 90°, and the angles of traverse β1 and β2 thereofare also set within the range of 45° to 90°. Preferably, the respectiveangles of dip α1 and α2 of the gas flows G1 and G2 are set to 45°, andthe angles of traverse β1 and β2 thereof are set to 90°. The angles ofdip α1 and α2 may differ from each other, and the angles of traverse β1and β2 may differ from each other.

The angle of dip αL of the liquid flow L1 is set within the range of 30°to 90°, and the angle of traverse β3 thereof is set within the range of0° to 45°. Preferably, the angle of dip αL and the angle of traverse βLare each set to 45°.

FIGS. 7 and 8 each illustrate an example of how the gas flows G1 and G2of the inert gas and the liquid flow L1 of the processing liquid aredischarged. The circles indicated as the nozzles 41, 42, and 51 crepresent the outlets of the nozzles 41, 42, and 51 c which areprojected onto the substrate W. Although the shape of the projectedoutlet varies depending on the shape, direction, or the like of theoutlet, it is indicated as a circle. The regions of the substrate W withwhich the gas flows G1 and G2 and the liquid flow L1 come into contactare indicated as the respective circles surrounding the positions P1,P2, and PL1. The position P1 is located upstream from the position PL1in the direction of rotation of the substrate W, and the position P2 islocated upstream from the position P1 in the direction of rotation ofthe substrate W.

In the example illustrated in FIG. 7, the outlets of the nozzles 41 and42 are arranged along the radial direction of the substrate W. The gasflow G1 discharged from the nozzle 41 comes into contact with theposition P1, and the gas flow G2 discharged from the nozzle 42 comesinto contact with the position P2. The positions of the outlets of thenozzles 41 and 42 may differ from each other in the radial direction ofthe substrate W, as described above.

In the example illustrated in FIG. 8, the gas flow G1 and the gas flowG2 are discharged at different angles of traverse. The outlets of thenozzles 41 and 42 are located at the positions different from each otheralong the direction of rotation of the substrate W. The outlet of thenozzle 42 is located upstream from the outlet of the nozzle 41 in thedirection of rotation of the substrate W. In the example of FIG. 8,specifically, the gas flow G1 is discharged at an angle of traverse of90°, and the gas flow G2 is discharged at an angle of traverse of 45°.In other words, the angle of traverse of the gas flow G2 is smaller thanthe angle of traverse of the gas flow G1. In this case, the gas flow G2has the speed components, namely, a speed component directed along thediameter of the substrate W toward the outside of the substrate W, and aspeed component directed along the circumferential direction of thesubstrate W toward the downstream side in the direction of rotation.Thus, as similarly to the gas flow G1, for example, a difference inspeed between the residual processing liquid and the gas flow G2 in thedirection of rotation of the substrate W is smaller than in the case inwhich the gas flow G2 is discharged at an angle of traverse of 90°. Thegas flow G2 thus drains the residual processing liquid out of thesubstrate W while restricting the generation of splashes when the gasflow G2 comes into contact with the liquid film of the residualprocessing liquid, thus reducing the thickness of the liquid film of theresidual processing liquid.

1-3. Restriction of Splashes

The processing liquid discharge mechanism 830 of the substrateprocessing apparatus 1 discharges the liquid flow L1 of the processingliquid such that the liquid flow L1 comes into contact with the positionPL1 in the rotation path of the peripheral portion of the upper surfaceof the substrate W being rotated. The discharged liquid flow L1 adheresto the position of discharge on the peripheral portion of the uppersurface (more strictly, processing region S3) of the substrate W in theform of a liquid film, and moves in the circumferential direction of thesubstrate W together with the peripheral portion of the substrate W.

A gas flow is caused to come into contact with such a liquid film of theresidual processing liquid from above to generate a gas flow flowingfrom the position with which the gas flow has come into contact towardthe outside of the substrate W, thereby blowing off a portion of theprocessing liquid, with which the gas flow has come into contact, towardthe outside of the substrate W. This results in a reduced thickness ofthe portion of the liquid film with which the gas flow comes intocontact. As described above, the width of the gas flow of the inert gasis set to be larger than the width of the liquid flow L1 of theprocessing liquid discharged onto the position PL1. In this case, thewidths of the gas flows G1 and G2 are larger than the width of theliquid film of the residual processing liquid that adheres to theperipheral portion of the upper surface of the substrate W. This alsocauses the processing liquid to move from the position, with which thegas flow comes into contact, to the portions that are located upstreamand downstream from the portion, with which the gas flow comes intocontact, of the liquid film of the residual processing liquid in thedirection of rotation of the substrate W (also merely referred to as“adjacent portions”), resulting in increased thicknesses of the liquidfilms of the adjacent portions. This causes the liquid film to becomewavy at the portion with which the gas flow comes into contact and itsadjacent portions. In this case, splashes normally occur mainly from theadjacent portions of the liquid film and scatter toward theirsurroundings.

The liquid at the portion with which the gas flow comes into contact isblown off more efficiently as the gas flow that comes into contact witha unit area of the surface of the liquid film has higher kinetic energy,thus reducing the thickness of the liquid film and increasing the filmthicknesses of the adjacent portions that are adjacent to the portionwith which the gas flow comes into contact. If the thickness of theliquid film of the residual processing liquid is constant, larger wavesare thus generated in the liquid film as the gas flow that comes intocontact with a unit area of the liquid film has higher kinetic energy,increasing an amount and a speed of the splashes of the residualprocessing liquid generated from the waves.

The thickness of the liquid film formed on the peripheral portion of theupper surface of the rotating substrate W has an upper limit, and thus,if the gas flow that comes into contact with the unit area of the liquidfilm has constant kinetic energy, the waves generated in the liquid filmnormally become larger as the liquid film is thicker. This increases anamount and a speed of the splashes generated from the waves.

If the thickness of the liquid film is small, splashes are less likelyto occur even when the liquid is blown off momentarily by a gas flowwith high kinetic energy, that is, a strong gas flow. On the other hand,if the thickness of the liquid film is large, splashes are likely tooccur due to the liquid film becoming wavy. However, if a gas flow withlow kinetic energy, that is, a weak gas flow is brought into contactwith the liquid film, small waves are generated in the portion withwhich the gas flow comes into contact and its adjacent portions, thusenabling the liquid film to become thinner gradually while restrictingsplashes.

In other words, to efficiently drain the residual processing liquid outof the substrate W while restricting the generation of splashes of theresidual processing liquid, the processing liquid needs to be drainedout efficiently by bringing a gas flow with low kinetic energy (weak gasflow) into contact with the portion with a thick liquid film andbringing a gas flow with high kinetic energy (strong gas flow) intocontact with the portion with a thin liquid film. It should be notedthat the thickness of the liquid film of the residual processing liquidalso varies depending on whether the surface of the substrate W ishydrophilic or hydrophobic. Specifically, if the substrate W has ahydrophilic surface, the residual processing liquid tends to spreadacross the surface of the substrate W, thus reducing the thickness ofthe liquid film. On the other hand, if the substrate W has a hydrophobicsurface, the processing liquid rises from the surface of the substrateW, thus increasing the thickness of the liquid film.

The gas discharge mechanism 440 of the substrate processing apparatus 1discharges the gas flows G1 and G2 of the inert gas to efficiently drainthe residual processing liquid out of the substrate W while restrictingthe generation of splashes of the residual processing liquid.Specifically, the gas discharge mechanism 440 discharges the gas flowsG1 and G2 such that the gas flow G1 comes into contact with the liquidfilm of the residual processing liquid at the position P1 upstream fromthe position PL1 in the direction of rotation of the substrate W, andthat the gas flow G2 comes into contact with the liquid film of theresidual processing liquid at the position P2 further upstream from theposition P1. The kinetic energy (more specifically, the kinetic energyof the gas flow discharged through the outlet per unit time) when thegas flow G1 or G2 is discharged is proportional to the product of thecross-sectional area of the outlet of the nozzle 41 or 42 and the cubeof the flow speed in discharge. The kinetic energy of the gas flow thatcomes into contact with the unit area of the liquid film per unit timeis also proportional to the cube of the flow speed of the gas flow. Thedischarge mechanism 440 discharges the gas flows G1 and G2 such that thekinetic energy of the gas flow G2 when the gas flow G2 is discharged islower than the kinetic energy of the gas flow G1 when the gas flow G1 isdischarged. More specifically, the gas discharge mechanism 440discharges the gas flows G1 and G2 such that the kinetic energy of aportion of the gas flow G2, which is discharged from the unitcross-sectional area of the outlet per unit time, is lower than thekinetic energy of a portion of the gas flow G1, which is discharged fromthe unit cross-sectional area of the outlet per unit time.

In the substrate processing apparatus 1, the gas flow G2 with kineticenergy lower than that of the gas flow G1 comes into contact with theliquid film of the residual processing liquid at the position P2 earlierthan the gas flow G1. Thus, the film thickness of the residualprocessing liquid can be reduced while restricting the generation ofsplashes that arrive at the to-be-protected region S4 (more strictly,splashes with speed at which splashes can arrive at the to-be-protectedregion S4) from the wave generated on the liquid film by the gas flowG2.

Then, at the position P1 downstream from the position P2, the gas flowG1 comes into contact with the liquid film of the processing liquid witha reduced film thickness. The gas flow G1, which has higher kineticenergy than the gas flow G2, can drain the residual processing liquidout of the substrate W more efficiently. The processing liquid isthinner than in the case in which the gas flow G2 comes into contactwith the processing liquid, resulting in a smaller wave generated in theliquid film by the gas flow G1. The gas flow G1 thus drains most of theresidual processing liquid out of the substrate W while restricting thegeneration of splashes that arrive at the to-be-protected region S4.

This restricts a collision of a fresh processing liquid, which isdischarged so as to come into contact with the position PL1 downstreamfrom the position P1, with the residual processing liquid. Theperipheral portion of the upper surface of the substrate W is thusprocessed while restricting the processing liquid from entering theto-be-protected region S4 of the upper surface of the substrate W. Thekinetic energy of the gas flow G1 (strictly, the kinetic energy of aportion of the gas flow of the gas flow G1, which is discharged per unittime from the unit cross-sectional area of the nozzle 41) is preferablyset to, for example, 1.2 to 8 times the kinetic energy of the gas flowG2 (strictly, the kinetic energy of a portion of the gas flow G2, whichis discharged from the unit cross-sectional area of the nozzle 42 perunit time). In this case, the ratio of the kinetic energy per unitvolume of the gas flow is 1.2 to 4 times.

If the residual processing liquid is drained out of the substrate W atan extremely high speed, a part of the residual processing liquid may bescattered toward the substrate W by being reflected upon the splashguard 31 and arrive at the portion, onto which the gas flow has not beendischarged, of the upper surface of the substrate W. The kinetic energyof the gas flow is thus preferably set such that the residual processingliquid reflected upon the splash guard 31 toward the substrate W willnot arrive at the substrate W.

Herein, the flow rate of a gas flow is proportional to the product ofthe cross-sectional area and flow speed of the gas flow. Increasing theflow rate of the gas flow thus also increases the kinetic energy of thegas flow. The gas flows G1 and G2 can thus be discharged such that theflow rate of the gas flow when the gas flow G2 is discharged is lowerthan the flow rate of the gas flow G1 when the gas flow G1 isdischarged. For example, the flow rate of the gas flow G1 is set to 1.1to 2 times the flow rate of the gas flow G2.

Reducing the flow speed of the gas flow or reducing the cross-sectionalarea of the gas flow can also reduce the flow rate. Reducing the flowspeed reduces the kinetic energy of the gas flow that comes into contactwith a unit area of the liquid film of the residual processing liquidper unit time. Thus, the flow speed of the gas flow G2 is preferably setto be lower than the flow speed of the gas flow G1 to set the flow rateof the gas flow G2 to be lower than the flow rate of the gas flow G1. Inthis case, the weak gas flow G2 can be discharged in a wide rangecompared with the gas flow G1 by setting the cross-sectional area of thegas flow G2 to be larger than the cross-sectional area of the gas flowG1, thereby reducing the liquid film while restricting splashes from theliquid film with which the gas flow G2 has come into contact.

The gas flow has higher kinetic energy as the gas flow has higher flowspeed. The gas flows G1 and G2 can thus be discharged such that the flowspeed of the gas flow G2 when the gas flow G2 is discharged is lowerthan the flow speed of the gas flow G1 when the gas flow G1 isdischarged. For example, the flow speed of the gas flow G1 is set to be1.1 to 2 times the flow speed of the gas flow G2.

1-4. Another Example of Nozzle of Gas Discharge Mechanism

FIG. 9 (FIG. 11) is a perspective view of the distal-end side portions(the portions including the outlets) of nozzles 41X and 42X (41Y and42Y) as an example of the nozzles that can be included in the gasdischarge mechanism 440 in place of the nozzles 41 and 42 of FIG. 1.FIG. 10 (FIG. 12) schematically illustrates the positions at which thegas flows G1 and G2 respectively discharged from the nozzles 41X and 42X(41Y and 42Y) come into contact with the peripheral portion of thesubstrate W.

The nozzle 41X and the nozzle 42X illustrated in FIG. 9 each have acylindrical outer shape. The diameter of the outlet of the nozzle 41X issmaller than the diameter of the outlet of the nozzle 42X, and the axisof the nozzle 41 X coincides with the axis of the nozzle 42X. In otherwords, the side wall of the nozzle 41X is surrounded by the side wall ofthe nozzle 42X. The respective outlets of the nozzles 41X and 42X areopposed to the peripheral portion of the upper surface of the substrateW. The nozzle 41X discharges the columnar gas flow G1, and the nozzle42X discharges the tubular gas flow G2 having a ring-shaped crosssection surrounding the gas flow G1. The gas flow G2 flows along theaxis line of the nozzle 42 while spreading outward from the axis line.The kinetic energy of the gas flow G2 when the gas flow G2 is dischargedis lower than the kinetic energy of the gas flow G1 when the gas flow G1is discharged.

The gas flow G1 discharged from the nozzle 41X comes into contact withthe position P1 upstream from the position PL1 with which the liquidflow L1 comes into contact, and a part of the gas flow G2 dischargedfrom the nozzle 42X comes into contact with the position P2 furtherupstream from the position P1. Although a part of the gas flow G2 alsocomes into contact with the side downstream from the position P1 withwhich the gas flow G1 comes into contact, the residual processing liquidin the peripheral portion of the substrate W can be reduced whilerestricting splashes by a part of the gas flow G2 that comes intocontact with the position P2 upstream from the position P1 and the gasflow G1 that comes into contact with the position P1. Thus, the utilityof the substrate processing apparatus 1 is not impaired. The use of thenozzles 41X and 42X causes a part of the gas flow G2 to come intocontact with the substrate W again on the side downstream from theposition P1, thereby further reducing the residual processing liquid.

The nozzles 41Y and 42Y illustrated in FIG. 11 are tubular nozzles thatare longer along the periphery of the substrate W, each of which has acircular-arc-shaped cross-section with a small width in the radialdirection of the substrate W. The outlets of the nozzles 41Y and 42Y areopposed to the peripheral portion of the substrate W. The nozzles 41 Yand 42Y are partitioned by a partition wall axially extended such thatthe cross-sections of the respective flow paths are adjacent to eachother along the coaxial circular arc.

The nozzles 41Y and 42Y respectively discharge the gas flows G1 and G2each having a circular-arc-shaped cross-section along the shape of theperiphery of the substrate W. The gas flow G2 is lower than the gas flowG1 in the kinetic energy in discharge.

The gas flow G1 discharged from the nozzle 41Y comes into contact withthe position P1 upstream from the position PL1 with which the liquidflow L1 comes into contact, and the gas flow G2 discharged from thenozzle 42Y comes into contact with the position P2 further upstream fromthe position P1. The gas flow G2 with low kinetic energy can reduce theresidual processing liquid while restricting splashes of the residualprocessing liquid that arrive at the to-be-protected region S4. Most ofthe residual processing liquid that has not been removed by the gas flowG2 and has remained in the substrate W is removed from the substrate Wby the gas flow G1 with kinetic energy higher than that of the gas flowG2. The residual processing liquid also has a liquid film whosethickness has been reduced, thus restricting the generation of splashesthat arrive at the to-be-protected region S4 even when the gas flow G1comes into contact with the to-be-protected region S4. The gas flows G1and G2 each come into contact with the liquid film in the form of across-sectional shape elongated in the circumferential direction of thesubstrate W, and thus, the kinetic energy of the gas flow G1 and thekinetic energy of the gas flow G2 are dispersed more than in the case inwhich the gas flows G1 and G2 come into contact with narrow areas.Moreover, the gas comes into contact with the area longer in thecircumferential direction of the substrate W than in the case in whichthe gas flows G1 and G2 come into contact with narrow areas. Thus, evenwhen the kinetic energy per unit area of each gas flow is reduced, eachgas flow comes into contact with the liquid film of the residualprocessing liquid for a longer period of time, thus sufficientlyremoving the residual processing liquid.

1-5. Operation of Substrate Processing Apparatus

FIG. 13 is a flowchart illustrating an example operation in which thesubstrate processing apparatus 1 processes a substrate with a processingliquid. The operation of the substrate processing apparatus 1 will bedescribed below with reference to FIG. 13. Before the operationillustrated in FIG. 13, the substrate W has been transferred into thesubstrate processing apparatus 1 to be held on the spin chuck 21. Thenozzle heads 48 to 50 have been arranged at the processing positions bythe nozzle moving mechanism 6, and the splash guard 31 has been arrangedat the upper position by the guard drive mechanism 32.

When the process illustrated in FIG. 13 is started, the rotatingmechanism 231 of the substrate processing apparatus 1 starts rotatingthe spin chuck 21 holding the substrate W (step S110). The rotationalspeed of the substrate W is set to, for example, 1000 rotations perminute.

Then, the gas discharge mechanism 440 starts discharging the gas flowsG1 and G2 of an inert gas from the nozzles 41 and 42 of the nozzle head48, and simultaneously, the gas discharge mechanism 443 startsdischarging the gas flow G3 of the inert gas from the nozzle 43 of thenozzle head 49 (step S120). The nozzle 43 discharges the inert gas ontothe central portion of the upper surface of the substrate W from aboveto generate the gas flow G3 spreading from the central portion of thesubstrate W toward the periphery of the substrate W. The flow rate ofthe gas flow G3 when the gas flow G3 is discharged from the nozzle 43 ishigher than the flow rates of the gas flows G1 and G2 when the gas flowsG1 and G2 are discharged.

After the gas discharge mechanisms 440 and 443 have started dischargingthe gas flows G1, G2, and G3, the heating mechanism 7 starts heating theperipheral portion of the substrate W by the heater 71. After thetemperature of the peripheral portion of the substrate W has risen andbecome stable after a lapse of time, the processing liquid dischargemechanism 830 discharges the liquid flow L1 of the processing liquidsuch that the liquid flow L1 comes into contact with the peripheralportion of the upper surface of the substrate W (more specifically, theprocessing region S3 of the peripheral portion of the upper surface onthe side closer to the end face of the substrate W), thus processing theperipheral portion of the upper surface (step S130). Specifically, theprocessing liquid discharge mechanism 830 discharges the liquid flow L1from one nozzle (in FIG. 1, the nozzle 51 c) among the nozzles 51 a to51 d in accordance with the control of the control unit 130. The liquidflow L1 is discharged so as to come into contact with the position PL1defined in the rotation path of the peripheral portion of the uppersurface (more specifically, the processing region S3) of the substrateW. The cross-sectional size and flow rate of the liquid flow L1 are setin advance such that the width of the liquid film, which turns from theliquid flow L2 and adheres to the peripheral portion of the substrate,is accommodated in the processing region S3. The liquid flow L1 comesinto contact with the position PL1 and then forms a liquid film on theprocessing region S3. The liquid film of the processing liquid moves inthe circumferential direction of the substrate W while adhering to theperipheral portion of the substrate W along with the rotation of thesubstrate W.

From the viewpoint of improving the processing rate of the substrate W,the discharged processing liquid preferably stays at the position ofdischarge in the processing region S3 for the longest possible period oftime. The central angle, which is formed between the straight lineconnecting the position PL1 in the rotation path and the center c1 ofthe substrate W and the straight line connecting the position onto whichthe liquid flow L1 has been discharged and the center c1, graduallyincreases along with the rotation of the substrate W. For example, 80%of the processing liquid discharged onto the processing region S3 isdrained out of the substrate W mainly by the centrifugal forceassociated with the rotation of the substrate W while the substrate Wrotates until the central angle reaches 90°. After that, theliquid-film-shaped processing liquid that has not been drained out andhas remained at the substrate W also moves along with the rotation ofthe substrate W while being gradually drained out of the substrate W andsimultaneously adhering to the processing region S3, thus contributingto processing of the substrate W during the process.

The gas flow G1 (G2), whose discharge has been started from the nozzle41 (42) in step S120, comes into contact with the liquid film of theresidual processing liquid at the position P1 (P2) upstream from theposition PL1 in the direction of rotation of the substrate W along thecircumferential direction of the substrate W in the rotation path of thesubstrate W. The position P2 is located upstream from the position P1.Subsequently, the gas flow G1 (G2) flows from the position P1 (P2)toward the periphery of the substrate W by, for example, its dischargedirection and the centrifugal force associated with the rotation of thesubstrate W. In other words, the gas discharge mechanism 440 dischargesthe gas flow G1 of the inert gas from above onto the position P1upstream from the position PL1, at which the processing liquid lands, inthe direction of rotation of the substrate W in the rotation path of thesubstrate W, thereby directing the gas flow G1 from the position P1toward the periphery of the substrate W. Additionally, the gas dischargemechanism 440 discharges the gas flow G2 of the inert gas from abovetoward the position P2 upstream from the position P1 in the direction ofrotation of the substrate W in the rotation path of the substrate W,thereby directing the gas flow G2 from the position P2 toward theperiphery of the substrate W.

The gas flow G3 discharged from the nozzle 43 of the gas dischargemechanism 443 spreads from the central portion of the substrate W towardthe periphery of the substrate W due to the influence of, for example,the direction in which the gas flow G3 is discharged and the centrifugalforce associated with the rotation of the substrate W. In other words,the gas discharge mechanism 443 discharges the inert gas from above thecentral portion of the upper surface of the substrate W to generate thegas flow G3 spreading from the central portion toward the periphery ofthe substrate W.

The gas flow G2 first comes into contact with the liquid film of theresidual processing liquid in the peripheral portion of the substrate W.The gas flow G2 has low kinetic energy when it is discharged comparedwith the gas flow G1, thus draining the processing liquid out of thesubstrate while restricting the generation of splashes that arrive atthe to-be-protected region S4. This reduces the film thickness of theresidual processing liquid. The gas flow G1 comes into contact with theliquid film of the processing liquid that has not been drained out ofthe substrate W by the gas flow G2, at the position P1 downstream fromthe position P2. The gas flow G1 has high kinetic energy when it isdischarged compared with the gas flow G2, and thus, most of theremaining processing liquid is drained out of the substrate W by the gasflow G1. The liquid film of the residual processing liquid has beenthinned by the gas flow G2 before the gas flow G1 comes into contactwith the liquid film. This restricts the generation of splashes thatarrive at the to-be-protected region S4 even when the gas flow 01 comesinto contact with the liquid film of the residual processing liquid.

As described above, most of the processing liquid discharged at theposition PL1 so as to come into contact with the processing region S3 ofthe substrate W is drained out of the substrate W during one rotation ofthe substrate W. This restricts the splashes generated due to aprocessing liquid, which is newly discharged onto the position PL1,coming into contact with the residual processing liquid. Whiledischarging of the gas flows G1 to G3 and discharging of the liquid flowL1 are performed simultaneously, the rotating mechanism 231 repeatedlyrotates the substrate W in accordance with the control of the controlunit 130. For example, the gas flows G1 to G3 are dischargedrespectively at flow rates of 12 L/min, 4 L/min, and 30 L/min to 130L/min.

When the control unit 130 detects a lapse of a processing time requiredfor processing the substrate W, the processing liquid dischargemechanism 830 stops discharging the processing liquid. This completesthe process of step S130.

The rotating mechanism 231 stops rotating the spin chuck 21 (step S140),and the heating mechanism 7 stops heating the peripheral portion of thesubstrate W by the heater 71. The gas discharge mechanisms 440 and 443stop discharging the gas flows G1 to G3 (step S150). As a result, theoperation illustrated in FIG. 13 ends.

After that, the nozzle moving mechanism 6 and the guard drive mechanism32 respectively move the nozzle heads 48 to 50 and the splash guard 31to the retreat positions. The substrate W is removed from the spin chuck21 to be transferred from the substrate processing apparatus 1.

Although the substrate processing apparatus 1 includes the nozzle 43that discharges the gas flow G3 of the inert gas, the substrateprocessing apparatus 1 may include no nozzle 43. In such a case, thesubstrate processing apparatus 1 may include no arm 62 and no nozzlehead 49.

Although the nozzles 41 and 42 are held by the nozzle head 48 and movedtogether by the arm 61, another configuration may be employed in whichthe nozzles 41 and 42 are held by different nozzle heads and movedindividually by different arms.

Although the substrate processing apparatus 1 discharges the nitrogengas as the gas flows G1 to G3, at least one gas flow of the gas flows G1to G3 may be an inert gas different from the inert gas of the other gasflows.

Although the nozzles 41 and 42 that respectively discharge the gas flowsG1 and G2 of the inert gas and the nozzles that discharge the processingliquid are held by the different nozzle heads 48 and 50 in the substrateprocessing apparatus 1, another configuration may be employed in whichthe nozzle 41, the nozzle 42, and the nozzles that discharge theprocessing liquid are held by the same nozzle head and moved together byan arm or the like.

The nozzles 41Y and 42Y, which are adjacent to each other, are separatenozzles. For example, one nozzle having an outlet elongated in thecircumferential direction of the substrate may discharge the gas flow G2and the gas flow G2 respectively from the upstream portion and thedownstream portion thereof in the direction of rotation of the substrateW. Such nozzles are achieved by, for example, providing a structure thatwill serve as a resistance on the downstream side in the flow path suchthat the resistance experienced by the gas flowing through the upstreamportion of the flow path is higher than that through the downstreamportion.

Between the nozzles 41 and 42 or between the nozzles 41Y and 42Y, atleast one additional nozzle may be provided that discharges a gas flowof an inert gas such that the gas flow comes into contact with theperipheral portion of the substrate W. The kinetic energy of the gasflow discharged from this at least one additional nozzle may be lower orhigher than the kinetic energy of the gas flow G2 discharged from thenozzle 42. This at least one additional nozzle preferably discharges agas flow such that the kinetic energy of the gas flow of the inert gasdischarged onto the peripheral portion of the substrate W becomes highersuccessively from the upstream side to the downstream side in thedirection of rotation of the substrate W.

In the substrate processing apparatus according to the first embodimentconfigured as described above, at the position P2, the gas flow G2 withkinetic energy lower than that of the gas flow G1 comes into contactwith the liquid film of the residual processing liquid at the peripheralportion of the substrate W. This causes the residual processing liquidto be drained out of the substrate W while restricting the generation ofsplashes of the residual processing liquid that can arrive at theto-be-protected region S4, thus reducing the film thickness of theresidual processing liquid. Consequently, the gas flow G1 with highkinetic energy is brought into contact with the portion at which thefilm thickness of the residual processing liquid has been reduced at theposition P1 on the downstream side, thereby draining most of theresidual processing liquid out of the substrate W while restricting thegeneration of splashes of the residual processing liquid that can arriveat the to-be-protected region S4. This restricts the generation ofsplashes that can arrive at the to-be-protected region S4 of thesubstrate W due to a collision between a processing liquid newlydischarged onto the position PL1 on the further downstream side and theresidual processing liquid. The peripheral portion of the upper surfaceof the substrate W is thus processed while restricting the processingliquid from entering the to-be-protected region S4 of the upper surfaceof the substrate W.

In the substrate processing apparatus according to the first embodimentconfigured as described above, the flow rate of the second gas flow whenthe second gas flow is discharged is lower than the flow rate of the gasflow G1 when the gas flow G1 is discharged. The second gas flow thusdrains the residual processing liquid out of the substrate W whilerestricting the generation of splashes that can arrive at theto-be-protected region S4, thereby reducing the film thickness of theresidual processing liquid.

In the substrate processing apparatus according to the first embodimentconfigured as described above, the flow speed of the second gas flowwhen the second gas flow is discharged is lower than the flow speed ofthe gas flow G1 when the gas flow G1 is discharged. The second gas flowthus drains the residual processing liquid out of the substrate W whilerestricting the generation of splashes that can arrive at theto-be-protected region S4, thereby reducing the film thickness of theresidual processing liquid.

In the substrate processing apparatus according to the first embodimentconfigured as described above, the gas discharge mechanism 443discharges an inert gas from above the central portion of the uppersurface of the substrate W to generate a gas flow spreading from abovethe central portion of the substrate W toward the periphery of thesubstrate W. The gas flow generated by the gas discharge mechanism 443further restricts the splashes that are generated when the second gasflow, the gas flow G1, and a fresh processing liquid sequentially comeinto contact with the residual processing liquid from arriving at theto-be-protected region S4.

In the substrate processing apparatus according to the first embodimentconfigured as described above, the flow rate of a gas flow dischargedfrom the gas discharge mechanism 443 when the gas flow is discharged ishigher than the flow rate of any of the flow rate of the gas flow G1when the gas flow G1 is discharged and the flow rate of the second gasflow when the second gas flow is discharged. A large amount of gas flowis supplied to the respective parts of the peripheral portion also inthe case in which the gas flow generated by the gas discharge mechanism443 spreads radially from the central portion of the substrate W towardthe peripheral portion of the substrate W.

2. Second Embodiment

2-1. Configuration of Substrate Processing Apparatus 1A

The configuration of a substrate processing apparatus 1A will bedescribed with reference to FIGS. 2 to 4 and 14. FIGS. 14, 2, and 3 areviews for explaining the configuration of the substrate processingapparatus 1A according to an embodiment. FIGS. 14 and 2 are a schematicside view and a schematic top view, respectively, of the substrateprocessing apparatus 1A. FIG. 3 is a schematic perspective view of thesubstrate processing apparatus 1A as viewed from diagonally above. FIG.4 is a schematic top view of a substrate W illustrating an example of apositional relationship among positions at which a liquid flow of aprocessing liquid and gas flows of an inert gas that are discharged fromthe substrate processing apparatus 1A come into contact with theperipheral portion of the substrate W.

FIGS. 14, 2, and 3 illustrate a state in which the substrate W is beingrotated in a predetermined direction of rotation (the direction of thearrow AR1) about a rotation axis a1 by a spin chuck 21, with nozzleheads 48 to 50 arranged at their respective processing positions. InFIG. 2, the nozzle heads 48 to 50 arranged at the retreat positions andthe like are indicated by the phantom lines. FIGS. 2 and 3 do notillustrate partial components of the substrate processing apparatus 1A,such as a scatter prevention unit 3.

The substrate processing apparatus 1A includes a rotary holdingmechanism 2, the scatter prevention unit 3, a surface protection unit 4,a processing unit 5, a nozzle moving mechanism 6, a heating mechanism7A, and a control unit 130A. These units 2 to 6 and 7A are electricallyconnected to the control unit 130A and operate in response toinstructions from the control unit 130A. The control unit 130A isconfigured similarly to the control unit 130 of the substrate processingapparatus 1. In the control unit 130A, the CPU serving as a main controlunit performs computations in accordance with the procedure described inthe program. The control unit 130A thus controls the respective units ofthe substrate processing apparatus 1A.

The units 2 to 6 of the substrate processing apparatus 1A are configuredand operate similarly to those of the units 2 to 6 of the substrateprocessing apparatus 1. The substrate processing apparatus 1A includesthe heating mechanism 7A in place of the heating mechanism 7 of thesubstrate processing apparatus 1. The description of the units 2 to 6 ofthe substrate processing apparatus 1A will be omitted, and the heatingmechanism 7A will now be described.

Heating Mechanism 7A

The heating mechanism 7A is provided below the peripheral portion of thelower surface of the substrate W. The heating mechanism 7A includes anannular heater 71A extending in the circumferential direction of thesubstrate W along the peripheral portion of the lower surface of thesubstrate W, a gas discharge mechanism (“shielding gas dischargemechanism”) 444, and an electric circuit (not shown) that supplies powerto the heater 71A in accordance with the control of the control unit130A.

FIGS. 15 to 17 are schematic top views of the heater 71A of the heatingmechanism 7A. FIG. 15 illustrates a heating element 73 and a heatingflow path 74 of the heater 71A. For easy viewing, FIG. 16 does notillustrate the heating flow path 74 of FIG. 15, and FIG. 17 does notillustrate the heating element 73 of FIG. 15. The heating element 73 isillustrated as a region in which the heating element 73 is arranged(arrangement region). The heating flow path 74 is arranged below theheating element 73.

FIGS. 18 and 19 are schematic cross-sectional views of the heater 71A ofthe heating mechanism 7A. FIG. 18 is a longitudinal cross-sectional viewof the heater 71A taken along the lines I-I and II-II of FIG. 15, andFIG. 19 is a longitudinal cross-sectional view of the heater 71A takenalong the lines and IV-IV of FIG. 15.

The heater 71A is arranged annularly (more specifically, in an annularbelt shape) around the spin chuck 21 below the peripheral portion of thelower surface so as to be opposed to the portion, which is not incontact with the upper surface of the spin chuck 21, of the lowersurface of the substrate W in a contactless manner. The heater 71A hasan annular plate shape. An opposed surface (upper surface) S7 of theheater 71A is parallel to the lower surface of the substrate W. Theopposed surface S7 is opposed to the lower surface (that is, a surfaceopposite to the upper surface being a to-be-processed surface) of thesubstrate W with an interval of, for example, approximately 2 to 5 mm.

The heater 71A is held by a holding member (not shown) provided uprighton the casing 24. The heater 71A is provided to improve the processingrate of the substrate W with a chemical solution and heats theperipheral portion of the substrate W from the lower surface side. Theheating mechanism 7A further includes a moving mechanism (e.g., a motor,not shown). The moving mechanism moves the heater 71A upward or downwardto dispose the heater 71A at the processing position or the retreatposition below the processing position. The retreat position is aposition at which the heater 71A does not interfere with the transferpath of the substrate W when the substrate W is transferred to and fromthe substrate processing apparatus 1A. The heater 71A is supplied withpower while being arranged at the processing position. The heater 71Aaccordingly generates heat to heat the peripheral portion of thesubstrate W.

The gas discharge mechanism 444 supplies an inert gas to the heatingflow path 74 of the heater 71A. The inert gas is preheated by the heater71A while flowing through the heating flow path 74. The gas dischargemechanism 444 discharges the heated inert gas into a space V1 betweenthe upper surface (opposed surface S7) of the heater 71A and the lowersurface of the substrate W. The inert gas discharged into the space V1restricts the atmosphere around the heater 71A from entering the spaceV1 and also heats the substrate W.

The heater 71A is a resistance heater including a body portion 72 madeof silicon carbide (SiC) or ceramic and the heating element (e.g., aresistance heating element such as a nichrome wire) 73 built in the bodyportion 72. The heating element 73 is arranged below an annular (morespecifically, an annular-belt-shaped) portion of the opposed surface S7of the heater 71A except for the outer peripheral portion and the innerperipheral portion of the heater 71A, over the entire annular (morespecifically, annular-belt-shaped) arrangement region defined along theannular portion. The arrangement region for the heating element 73 isparallel to the lower surface of the substrate W and the opposed surfaceS7 of the heater 71A. Preferably, the substrate W is uniformly heatedwith ease if the arrangement region for the heating element 73 isparallel to the lower surface of the substrate W. Inside the heater 71A,a temperature sensor (not shown) is also arranged. The temperaturesensor measures the temperature of the heater 71A and transmits themeasurement result to the control unit 130A. The control unit 130Acontrols the power supply to the heating element 73 based on themeasurement result.

The heating flow path 74 is arranged along the heating element 73 belowthe heating element 73. In other words, the heating flow path 74 isarranged opposite to the substrate W relative to the heating element 73.In this case, the heating flow path 74 is not provided between thesubstrate W and the heating element 73, thus enabling the substrate W tobe heated uniformly. The heat radiation and heat transfer from theheating element 73 to the substrate W are not hindered by the inert gasflowing through the heating flow path 74. The heating flow path 74 maybe arranged between the substrate W and the heating element 73. Toconsider that the heating flow path 74 is arranged along the heatingelement 73, it suffices that the heating flow path 74 is arranged alongthe arrangement region for the heating element 73. The respectiveportions of the heating flow path 74 can be uniformly heated with easeif the heating flow path 74 is arranged along the heating element 73.Thee inert gas flowing through the each portion of the heating flow path74 is thus uniformly heated with ease.

The body portion 72 of the heater 71A includes, for example, a lowermember 72 a, a middle member 72 b, and an upper member 72 c sequentiallylayered from below to above. The members 72 a to 72 c are annularplate-shaped members extending in the circumferential direction of thesubstrate W along the peripheral portion of the lower surface of thesubstrate W.

On the upper surface of the lower member 72 a, a groove portion(“recess”) forming the heating flow path 74 is extended. The grooveportion has a bottom surface and a pair of side surfaces providedupright at the opposite widthwise ends of the bottom surface. The bottomsurface and the pair of side surfaces are a bottom surface and a pair ofside surfaces, respectively, of the heating flow path 74.

The middle member 72 b is bonded onto the lower member 72 a with, forexample, bolts (not shown). The upper surface of the lower member 72 aand the lower surface of the middle member 72 b adhere closely to eachother. The portion, which closes the groove formed in the upper surfaceof the lower member 72 a, of the lower surface of the middle member 72 bis a ceiling surface of the heating flow path 74. In the upper surfaceof the middle member 72 b, an annular and shallow recess in which theheating element 73 is to be arranged is provided along thecircumferential direction of the lower member 72 a. The heating element73 is arranged in the recess. The recess is an arrangement region forthe heating element 73.

The upper member 72 c is bonded onto the middle member 72 b in which theheating element 73 is arranged with, for example, bolts (not shown). Theupper surface of the middle member 72 b and the lower surface of theupper member 72 c adhere closely to each other except for in the recessprovided in the upper surface of the middle member 72 b. The uppersurface of the upper member 72 c is the opposed surface S7 of the heater71A.

In the example illustrated in FIG. 15, the heating flow path 74 isrepeatedly arranged as follows: it makes approximately one loop aroundthe inner peripheral surface S9 of the heater 71A in the circumferentialdirection, is then doubled back toward the outer peripheral surface S10of the heater 71A in the plane extending along the opposed surface S7,and makes approximately one loop around the heater 71A in the oppositedirection. Consequently, the heating flow path 74 is arranged across theinner peripheral surface S9 of the heater 71A and the outer peripheralsurface S10 of the heater 71A so as to make approximately four loops bybeing doubled back each time it makes approximately one loop around theinner peripheral surface S9 of the heater 71A in the circumferentialdirection of the heater 71A. The heating flow path 74 cuts across fourlocations of the longitudinal cross-section of the heater 71A in thecircumferential direction of the heater 71A. The four locations arearranged sequentially at intervals along the radial direction of theheater 71A. The innermost (innermost peripheral) portion, that is, theportion with the smallest diameter of the heating flow path 74 is, whenseen through from above, arranged between the inner periphery of theheater 71A and the inner periphery of the arrangement region for theheating element 73 along both of the inner peripheries. The outermost(outermost peripheral) portion, that is, the portion with the largestdiameter of the heating flow path 74 is, when seen through from above,arranged between the outer periphery of the arrangement region for theheating element 73 and the outer periphery of the heater 71A along bothof the outer peripheries.

As described above, the arrangement region for the heating element 73 isparallel to the lower surface of the substrate W. The heating flow path74 is arranged two-dimensionally along the heating element 73 below theheating element 73. To consider that the heating flow path 74 isarranged two-dimensionally, it suffices that an imaginary plane in whichthe heating flow path 74 is entirely arranged can be grasped. If theheating flow path 74 is arranged two-dimensionally along the heatingelement 73, the heating flow path 74 can be made longer, and thedistance from each portion of the heating flow path 74 to the heatingelement 73 can be made uniform. This facilitates sufficient heating ofthe inert gas flowing through each portion of the heating flow path 74by the heating element 73 and uniform heating of the inert gas flowingthrough each portion of the heating flow path 74 at each portion.

As a portion of the heating flow path 74, which is arranged below theheating element 73 along the heating element 73, is longer, the inertgas flowing through the heating flow path 74 is heated by the heatingelement 73 for a longer period of time. The path in which the heatingflow path 74 is arranged may be, for example, various arrangement pathssuch as a path looping in the circumferential direction of the heater71A while meandering below the heating element 73. Although the heatingflow path 74 makes approximately four loops around the inner peripheralsurface S9 of the heater 71A in the example illustrated in FIG. 17, thenumber of loops may be less than or more than four. Alternatively, theheating flow path 74 may be arranged along the heating element 73one-dimensionally or three-dimensionally. To consider that the heatingflow path 74 is arranged three-dimensionally, it suffices that athree-dimensional region in which the heating flow path 74 is entirelyarranged can be grasped.

In the lower portion of the heater 71A, an introduction hole 75 forintroducing an inert gas into the heating flow path 74 is formed. Theintroduction hole 75 at its lower end is open to the lower surface ofthe lower member 72 a and at its upper end is open to the bottom surfaceof an approximately central portion of the heating flow path 74 in thelongitudinal direction of the heating flow path 74. The lower end of theintroduction hole 75 is connected with the second end of a pipe 474. Theintroduction hole 75 is in communication with each of the pipe 474 andthe heating flow path 74. The inert gas supplied from the gas supplysource 454 of the gas discharge mechanism 444 through the pipe 474 isintroduced into the heating flow path 74 through the introduction hole75.

In the opposed surface S7 of the heater 71A, a plurality of (in theillustrated example, 12) outlets 78 and a plurality of (in theillustrated example, 12) outlets 79 are provided to be opposed to thelower surface of the substrate W.

The plurality of outlets 78 are provided in the outer peripheral portionof the heater 71A, and the plurality of outlets 79 are provided in theinner peripheral portion of the heater 71A. More specifically, theplurality of outlets 78 are, in a top view, distributed sparsely in thecircumferential direction of the heater 71A between the outer peripheryof the heater 71A and the outer periphery of the arrangement region forthe heating element 73. The plurality of outlets 79 are, in a top view,distributed sparsely in the circumferential direction of the heater 71Abetween the inner periphery of the heater 71A and the inner periphery ofthe arrangement region for the heating element 73. Consequently, theflow paths (through holes 76 and 77) connecting the outlet for the inertgas and the heating flow path 74 can be arranged easily, thus easilyachieving a configuration in which a gas is discharged from an outletformed in the opposed surface S7 of the heater 71A including the heater71A. Also, the heater 71A can be miniaturized easily.

The plurality of outlets 78 are connected with the outermost (outermostperipheral) portion of the heating flow path 74 through the plurality ofthrough holes 76. The plurality of outlets 79 are connected with theinnermost (innermost peripheral) portion of the heating flow path 74through the plurality of through holes 77. The plurality of throughholes 76 and 77 respectively pass through the upper member 72 c and themiddle member 72 b vertically. The plurality of through holes 76 areopen to the ceiling surface of the outermost portion of the heating flowpath 74. The plurality of through holes 77 are open to the ceilingsurface of the innermost portion of the heating flow path 74.

The gas discharge mechanism 444 includes a gas supply source 454, thepipe 474, a flow rate controller 484, an on/off valve 464, theintroduction hole 75, the heating flow path 74, the plurality of throughholes 76 and 77, and the plurality of outlets 78 and 79. The gas supplysource 454 supplies an inert gas (in the illustrated example, nitrogen(N₂) gas). The pipe 474 is connected at a first end to the gas dischargemechanism 444 and at a second end to the introduction hole 75.

At some midpoint in the pipe 474, the flow rate controller 484 and theon/off valve 464 are provided sequentially from the gas supply source454 side. The introduction hole 75, the heating flow path 74, thethrough hole 76, and the through hole 77 are provided in the heater 71A.The gas discharge mechanism 444 supplies an inert gas from the gassupply source 454 to the pipe 474. The flow rate controller 484 controlsthe flow rate of the gas flowing through the pipe 474. The inert gas isintroduced through the pipe 474 and the introduction hole 75 into anapproximately central portion of the heating flow path 74 in thelongitudinal direction of the heating flow path 74. The introduced inertgas is divided into two gas flows flowing in the opposite directionsalong the path of the heating flow path 74 to flow through the heatingflow path 74.

The gas that has flowed in one direction flows through the portion(specifically, the portion with the second smallest looping diameter) ofthe heating flow path 74 making approximately one loop around the heater71A below the heating element 73. During the flowing, the gas is heatedby the heating element 73 thereabove. Subsequently, the inert gas flowsthrough the portion (the portion with the smallest looping diameter)closest to the inner peripheral surface S9 of the heater 71A. Theportion of the heating flow path 74 closest to the inner peripheralsurface S9 is arranged slightly inward of the inner periphery of theheating element 73 (on the side closer to the rotary shaft 22), andthus, the inert gas is also heated when flowing through this flow path.The inert gas then passes through the plurality of through holes 77 tobe discharged through the plurality of outlets 79 into the space V1.

The gas that has been introduced into the heating flow path 74 and thenflowed in the other direction flows through the portion (the portionwith the second largest looping diameter) of the heating flow path 74making approximately one loop around the heater 71A below the heatingelement 73. During the flowing, the gas is heated by the heating element73. Subsequently, the inert gas flows through the outermost portion (theportion with the largest looping diameter) of the heating flow path 74.The outermost portion is arranged slightly outward of the outerperiphery of the heating element 73 (opposite to the rotary shaft 22),and thus, the inert gas is also heated when flowing through thisportion. The inert gas then passes through the plurality of throughholes 76 to be discharged into the space V1 through the plurality ofoutlets 78.

As described above, the inert gas discharged into the space V1 ispreheated by the heating element 73 while flowing through the heatingflow path 74. Thus, the gas can be heated sufficiently without anotherheater provided for heating the inert gas.

The flow rate controller 484 includes, for example, a flowmeter thatdetects the flow rate of a gas flowing through the pipe 474 and avariable valve that can adjust the flow rate of the gas in accordancewith a valve open/close amount. The control unit 130A controls theopen/close amount of the variable valve of the flow rate controller 484via a valve control mechanism (not shown) such that the flow ratedetected by the flowmeter of the flow rate controller 484 is equal to atarget flow rate. The control unit 130A sets a target flow rate within apredetermined range in accordance with the predetermined settinginformation to freely control the flow rate of the gas passing throughthe flow rate controller 484 within the predetermined range. The controlunit 130A also controls the on/off valve 464 between the open state andthe closed state via the valve control mechanism.

Thus, the control unit 130A controls how the gas flow G4 of the inertgas is discharged through the plurality of outlets 78 and 79 (such as adischarge start timing, a discharge end timing, and a discharge flowrate).

The electric circuit that supplies power to the heater 71A and themoving mechanism that moves the heater 71A upward or downward iselectrically connected to the control unit 130A and operates under thecontrol of the control unit 130A. In other words, the control unit 130Acontrols how the heater 71A heats the substrate W and the inert gas(such as the temperature of the substrate W and the temperature of thedischarged inert gas) and also controls the position of the heater 71A.

2-2. Action of Shielding Gas

FIG. 20 illustrates an example of the gas flow G4 of the inert gasdischarged into a space between the heater 71A and the substrate. Theheater 71A radiates rays of heat H1 onto the lower surface of thesubstrate W from the opposed surface S7 by heat generation of theheating element 73, thereby heating the substrate W. The inert gassupplied from the gas discharge mechanism 444 is introduced into theheating flow path 74 and is preheated by the heating element 73 whileflowing through the heating flow path 74. The heated gas passes throughholes 76 and 77 to be discharged through the outlets 78 and 79 into thespace V1 as the gas flow G4 of the inert gas.

The gas flow G4 flows from each of the outlets 78 and 79 toward theperiphery of the substrate W and the center of the substrate W. On theside close to the periphery of the substrate W relative to the heater71A and the side close to the center of the substrate W relative to theheater 71A, an atmosphere G9 of lower temperature than that of the gasflow G4 is present. The gas flow G4 discharged through the outlet 78 anddirected toward the periphery of the substrate W restricts theatmosphere G9 present on the side close to the periphery of thesubstrate W relative to the heater 71A from entering the space V1. Thegas flow G4 discharged through the outlet 79 and directed toward thecenter of the substrate W restricts the atmosphere G9 present on theside close to the center of the substrate W relative to the heater 71Afrom entering the space V1. This restricts a temperature drop of theperipheral portion of the substrate W. Thus, the heating efficiency ofthe substrate W by the heater 71A is restricted from dropping due to theatmosphere G9. The gas flow G4, which has been preheated, contributes toheating of the substrate W.

The inert gas discharged from the gas discharge mechanism 441 servers asa shielding gas to prevent the atmosphere G9 from entering the space V1,as well as a heating gas to heat the substrate W.

FIG. 21 graphically illustrates an example relationship between the flowrate of the gas flow G4 of the inert gas and the temperature of theperipheral portion of the substrate W. The flow rate of the gas flow G4of the inert gas (specifically, nitrogen gas) discharged onto the lowersurface of the substrate W through the outlets 78 and 79 of the heater71A is varied in four ways: 80 L/min, 60 L/min, 40 L/min, and 20 L/min.The temperature of the peripheral portion of the substrate W in FIG. 21is the temperature of the portion of the substrate W, which is 3 mminside of the periphery of the substrate W. The temperatures after 300seconds from the start of discharging of the gas flow G4 are measured.The exhaust pressure of a chamber that accommodates the substrateprocessing apparatus 1A is 250 Pa.

As illustrated in FIG. 21, as the flow rate of the gas flow G4 ishigher, the temperature of the peripheral portion of the substrate W ishigher. This reveals that by discharging the preheated gas flow G4through the outlets 78 and 79 of the heater 71A, the atmosphere G9 canbe restricted from entering the space V1, thereby efficiently heatingthe substrate W by the heater 71A.

2-3. Operation of Substrate Processing Apparatus

FIG. 22 is a flowchart illustrating an example operation in which thesubstrate processing apparatus 1A processes a substrate with aprocessing liquid. The operation of the substrate processing apparatus1A will be described below with reference to FIG. 22. Before theoperation illustrated in FIG. 22, the substrate W has been transferredto the substrate processing apparatus 1A to be held on the spin chuck21. The nozzle heads 48 to 50 have been arranged at the processingpositions by the nozzle moving mechanism 6, and the splash guard 31 isarranged at the upper position by the guard drive mechanism 32.

When the process illustrated in FIG. 22 is started, the rotatingmechanism 231 of the substrate processing apparatus 1A starts rotatingthe spin chuck 21 holding the substrate W (step S210). The rotationalspeed of the substrate W is set to, for example, 1000 rotations perminute.

Then, the gas discharge mechanism 440 starts discharging the gas flowsG1 and G2 of the inert gas from the nozzles 41 and 42 of the nozzle head48, and the gas discharge mechanism 443 starts discharging the gas flowG3 of the inert gas from the nozzle 43 of the nozzle head 49 (stepS220). The nozzle 43 discharges the inert gas onto the central portionof the upper surface of the substrate W from above to generate the gasflow G3 spreading from the central portion of the substrate W toward theperiphery of the substrate W. The flow rate of the gas flow G3 when thegas flow G3 discharged from the nozzle 43 is discharged is higher thanthe flow rates of the gas flows G1 and G2 when the gas flows G1 and G2are discharged.

After the discharge of the gas flows G1 to G3 has been started, theheating mechanism 7A starts heating the peripheral portion of thesubstrate W by the heater 71A. The heater 71A is heated to, for example,approximately 185°. The gas discharge mechanism 444 of the heatingmechanism 7A starts supplying the inert gas from the gas supply source454 at a flow rate of, for example, 40 L/min to 60 L/min to startdischarging the gas flow G4 through the plurality of outlets 78 and 79formed in the opposed surface S7 of the heater 71A (step S230). Theinert gas is heated to be higher than the processing temperature (e.g.,60° C. to 90° C.) of the substrate W.

After the temperature of the peripheral portion of the substrate W hasrisen and become stable after a lapse of time, the processing liquiddischarge mechanism 830 discharges the liquid flow L1 of the processingliquid (chemical solution) such that the liquid flow L1 comes intocontact with the peripheral portion of the upper surface of thesubstrate W (more specifically, the processing region S3 of theperipheral portion of the upper surface on the side closer to the endface of the substrate W), thus processing the peripheral portion of theupper surface (step S240). Specifically, the processing liquid dischargemechanism 830 discharges the liquid flow L1 from one nozzle (in FIG. 14,the nozzle 51 c) among the nozzles 51 a to 51 d in accordance with thecontrol of the control unit 130A. The liquid flow L1 is discharged so asto come into contact with a position PL1 defined in the rotation path ofthe peripheral portion of the upper surface of the substrate W (morespecifically, the processing region S3). The cross-sectional size andflow rate of the liquid flow L1 are set in advance such that the widthof the liquid film, which turns from the liquid flow L 1 and adheres tothe peripheral portion of the substrate W, fits in the processing regionS3. The liquid flow L1 comes into contact with the position PL1 and thenforms a liquid film on the processing region S3. The liquid film of theprocessing liquid moves in the circumferential direction of thesubstrate W while adhering to the peripheral portion of the substrate Walong with the rotation of the substrate W.

From the viewpoint of improving the processing rate of the substrate W,the discharged processing liquid preferably stays at the position ofdischarge in the processing region S3 for the longest possible period oftime. The central angle, which is formed between the straight lineconnecting the position PL1 in the rotation path and the center c1 ofthe substrate W and the straight line connecting the position onto whichthe liquid flow L1 has been discharged and the center c1, graduallyincreases along with the rotation of the substrate W. For example, 80%of the processing liquid discharged onto the processing region S3 isdrained out of the substrate W mainly by the centrifugal forceassociated with the rotation of the substrate W while the substrate Wrotates until the central angle reaches 90°. After that, theliquid-film-shaped processing liquid that has not been drained out andhas remained in the substrate W also moves along the circumferentialdirection of the substrate W while being gradually drained out of thesubstrate W and simultaneously adhering to the processing region S3,thus contributing to processing of the substrate W during the process.

The gas flow G1 (G2), whose discharge has been started from the nozzle41 (42) in step S220, comes into contact with the liquid film of theresidual processing liquid at the position P1 (P2) upstream from theposition PL1 in the direction of rotation of the substrate W along thecircumferential direction of the substrate W in the rotation path of thesubstrate W. The position P2 is upstream from the position P1.Subsequently, the gas flow G1 (G2) flows from the position P1 (P2)toward the periphery of the substrate W by, for example, its dischargedirection and the centrifugal force associated with the rotation of thesubstrate W. In other words, the gas discharge mechanism 440 dischargesthe gas flow G1 of the inert gas from above onto the position P1upstream from the position PL1, at which the processing liquid lands, inthe direction of rotation of the substrate W in the rotation path of thesubstrate W, thereby directing the gas flow G1 from the position P1toward the periphery of the substrate W. Additionally, the gas dischargemechanism 440 discharges the gas flow G2 of the inert gas from abovetoward the position P2 upstream from the position P1 in the direction ofrotation of the substrate W in the rotation path of the substrate W,thereby directing the gas flow G2 from the position P2 toward theperiphery of the substrate W.

The gas flow G3 discharged from the nozzle 43 of the gas dischargemechanism 443 spreads from the central portion of the substrate W towardthe periphery of the substrate W due to the influence of, for example,the direction in which the gas flow G3 is discharged and the centrifugalforce associated with the rotation of the substrate W. In other words,the gas discharge mechanism 443 discharges the inert gas from above thecentral portion of the upper surface of the substrate W to generate thegas flow G3 spreading from the central portion toward the periphery ofthe substrate W.

The gas flow G2 first comes into contact with the liquid film of theresidual processing liquid in the peripheral portion of the substrate W.The gas flow G2 has low kinetic energy when it is discharged comparedwith the gas flow G1, thus draining the processing liquid out of thesubstrate while restricting the generation of splashes that arrive atthe to-be-protected region S4. This reduces the film thickness of theresidual processing liquid. The gas flow G1 comes into contact with theliquid film of the processing liquid that has not been drained out ofthe substrate W by the gas flow G2 and has remained in the substrate W,at the position P1 downstream from the position P2. The gas flow G1 hashigh kinetic energy when it is discharged compared with the gas flow G2,and thus, most of the remaining processing liquid is discharged out ofthe substrate W by the gas flow G1. The liquid film of the residualprocessing liquid has been thinned by the gas flow G2 before the gasflow G1 comes into contact with the liquid film. This restricts thegeneration of splashes that arrive at the to-be-protected region S4 evenwhen the gas flow G1 comes into contact with the liquid film of theresidual processing liquid.

As described above, most of the processing liquid discharged at theposition PL1 so as to come into contact with the processing region S3 ofthe substrate W is drained out of the substrate W during one rotation ofthe substrate W. This restricts the splashes generated due to aprocessing liquid, which is newly discharged onto the position PL1,coming into contact with the residual processing liquid. Whiledischarging of the gas flows G1 to G3 and discharging of the liquid flowL are performed simultaneously, the rotating mechanism 231 repeatedlyrotates the substrate W in accordance with the control of the controlunit 130A. For example, the gas flows G1 to G3 are dischargedrespectively at flow rates of 12 L/min, 4 L/min, and 30 L/min to 130L/min.

When the control unit 130A detects a lapse of a processing time requiredfor processing the substrate W, the processing liquid dischargemechanism 830 stops discharging the processing liquid. This completesthe process of step S240.

The heating mechanism 7A stops supplying power to the heater 71A to stopheating the substrate W by the heater 71A and stops discharging the gasflow G4 by the gas discharge mechanism 444 (step S250).

The rotating mechanism 231 stops rotating the spin chuck 21 (step S260),and the heating mechanism 7A stops heating the peripheral portion of thesubstrate W by the heater 71A. The gas discharge mechanisms 440 and 443stop discharging the gas flows G1 to G3 (step S270). As a result, theoperation illustrated in FIG. 22 ends.

After that, the nozzle moving mechanism 6 and the guard drive mechanism32 respectively move the nozzle heads 48 to 50 and the splash guard 31to the retreat positions. The substrate W is removed from the spin chuck21 to be transferred from the substrate processing apparatus 1.

The gas discharge mechanism 444 discharges the gas flow G4 through theplurality of outlets 78 and 79 provided in the heater 71A, while thesubstrate W rotates. Thus, the gas discharge mechanism 444 may dischargethe gas flow G4 through a single outlet 78 and a single outlet 79provided in the heater 71A. Even when the gas flow G4 is discharged fromonly one outlet of the outlet 78 and the outlet 79, a temperature dropof the substrate W can be restricted more than in the case in which thegas flow G4 is not discharged. A flow path for the inert gas may beprovided between the opposed surface S7 of the heater 71A and theheating element 73 such that the gas flow G4 may be discharged throughthe outlet that is open to above the heating element 73.

The substrate processing apparatus 1A discharges the chemical solutionfrom the processing liquid discharge mechanism 830 onto the processingregion S3 of the upper surface (to-be-processed surface) of thesubstrate W and heats the substrate W from the lower surface of thesubstrate W by the heater 71A opposed to the lower surface of thesubstrate W. Also, the gas discharge mechanism 444 discharges the gasflow G4 of the heated inert gas into the space V1 between the opposedsurface S7 of the heater 71A and the lower surface of the substrate W.It should be noted that the to-be-processed surface may be the lowersurface of the substrate W. In other words, the processing liquiddischarge mechanism 830 may discharge the chemical solution onto theperipheral portion of the lower surface of the substrate W, the heater71A, which is opposed to the upper surface of the substrate W, may heatthe substrate W, and the gas discharge mechanism 444 may discharge thegas flow G4 into the space between the upper surface of the substrate Wand the lower surface (opposed surface) of the heater 71A.

The gas discharge mechanism 444 may discharge the inert gas preheatedby, for example, another heater different from the heater 71A into thespace V1. Specifically, the gas discharge mechanism 444 may preheat theinert gas supplied from the gas supply source 454 by the other heaterand, through the pipe outside of the heater 71A, discharge the heatedinert gas into the space V1 from the nozzle outside of the heater 71A.

The heater 71A may be provided so as to cover the entire surface, whichis opposite to the to-be-processed surface, of the substrate W. Theheater 71A can be provided between the lower surface of the substrate Wand the upper surface of the spin chuck 21 when the spin chuck 21, whichincludes a plurality of chuck pins, holds the substrate W such that thesubstrate W does not contact the upper surface of the spin chuck 21. Inthis case, the heater 71A is supported by a columnar support memberpassing through the inside of the rotary shaft 22 and the spin chuck 21.

Although the substrate processing apparatus 1A includes the nozzle 43that discharges the gas flow G3 of the inert gas, the substrateprocessing apparatus 1A may include no nozzle 43. In that case, thesubstrate processing apparatus 1A may include no arm 62 and no nozzlehead 49.

Although the nozzles 41 and 42 are held by the nozzle head 48 and movedtogether by the arm 61, another configuration may be employed in whichthe nozzles 41 and 42 are held by different nozzle heads and are movedindividually by different arms.

Although the substrate processing apparatus 1A discharges the nitrogengas as the gas flows G1 to G4, at least one gas flow of the gas flows G1to G4 may be an inert gas different from the inert gas of the other gasflows.

Although the nozzles 41 and 42 that respectively discharge the gas flowsG1 and G2 of the inert gas and the nozzles that discharge the processingliquid are held by the different nozzle heads 48 and 50 in the substrateprocessing apparatus 1, another configuration may be employed in whichthe nozzle 41, the nozzle 42, and the nozzles that discharge theprocessing liquid are held by the same nozzle head and moved together byan arm or the like.

In the substrate processing apparatus according to the second embodimentconfigured as described above, the gas flow G4 of the preheated inertgas is discharged into the space V1 between the opposed surface S7 ofthe heater 71A and the surface (to-be-protected surface), which isopposite to the to-be-processed surface, of the substrate W. Thisrestricts the atmosphere G9 from entering the space V1 to restrict adrop in the heating efficiency of the substrate W, and also restricts adrop in the heating efficiency also by the gas flow G4 of the inert gas.Thus, the substrate W can be processed while being efficiently heated.

In the substrate processing apparatus according to the second embodimentconfigured as described above, the gas discharge mechanism 444discharges the gas flow G4 of the inert gas preheated by the heater 71A.Thus, there is no need to separately provide the heater for heating theinert gas, reducing the cost of the substrate processing apparatus.

In the substrate processing apparatus according to the second embodimentconfigured as described above, the gas discharge mechanism 444 includesthe heating flow path 74 arranged along the heating element 73 of theheater 71A and discharges the inert gas heated by the heater 71A whenflowing through the heating flow path 74. This improves the heatingefficiency of the inert gas by the heater 71A.

In the substrate processing apparatus according to the second embodimentconfigured as described above, the heating flow path 74 is arrangedtwo-dimensionally along the heating element 73, thus further improvingthe heating efficiency of the inert gas by the heater 71A.

In the substrate processing apparatus according to the second embodimentconfigured as described above, the heating flow path 74 is arrangedopposite to the substrate W relative to the heating element 73, andthus, the heating element 73 efficiently heats both of the substrate Wand the inert gas.

In the substrate processing apparatus according to the second embodimentconfigured as described above, the gas discharge mechanism 444 includesthe outlets 78 and 79 respectively provided in the outer peripheralportion and the inner peripheral portion of the annular heater 71A anddischarges the inert gas through the outlets 78 and 79. This effectivelyrestricts the atmosphere G1 around the heater 71A from entering thespace V1 between the substrate W and the heater 71A. The substrate W istherefore heated efficiently.

3. Third Embodiment

3-1. Configuration of Substrate Processing Apparatus 1B

The configuration of a substrate processing apparatus 1B will bedescribed with reference to FIGS. 23 to 27. FIGS. 23 to 25 are views forexplaining the configuration of the substrate processing apparatus 1Baccording to an embodiment. FIGS. 23 and 24 are a schematic side viewand a schematic top view, respectively, of the substrate processingapparatus 1B. FIG. 25 is a schematic perspective view of the substrateprocessing apparatus 1B as viewed from diagonally above. FIGS. 26 and 27are a schematic top view and a schematic side view, respectively, of asubstrate W, which illustrate an example of a positional relationship ofthe positions at which a liquid flow of a processing liquid and gasflows of an inert gas that are discharged from the substrate processingapparatus 1B come into contact with the peripheral portion of thesubstrate W. FIG. 26 is a top view schematically illustrating positionsPL1, PL2, P3, and P4 at which the processing liquid, rinse liquid, andinert gas discharged from the substrate processing apparatus 1B comeinto contact with the peripheral portion of the substrate. FIG. 27 is aschematic side view illustrating a state in which the nozzlesindividually discharge the processing liquid and the like onto thepositions PL1, PL2, P3, and P4.

FIGS. 23 to 25 illustrate a state in which the substrate W is beingrotated in a predetermined direction of rotation (the direction of thearrow AR1) about a rotation axis al by a spin chuck 21, with nozzleheads 48B, 49, and 50 arranged at their respective processing positions.In FIG. 24, the nozzle heads 48B, 49, and 50 arranged at their retreatpositions and the like are indicated by phantom lines. FIGS. 24 and 25do not illustrate partial components of the substrate processingapparatus 1B, such as a scatter prevention unit 3.

The substrate processing apparatus 1B includes a rotary holdingmechanism 2, the scatter prevention unit 3, a surface protection unit4B, a processing unit 5, a nozzle moving mechanism 6, a heatingmechanism 7B, a rear surface protection unit 8, and a control unit 130B.These units 2, 3, 4B, 5, 6, 7B, and 8 are electrically connected to thecontrol unit 130B and operate in response to instructions from thecontrol unit 130B. The control unit 130B is configured similarly to thecontrol unit 130 of the substrate processing apparatus 1. In the controlunit 130B, the CPU serving as a main control unit performs computationsin accordance with the procedure described in the program. The controlunit 130B thus controls the respective units of the substrate processingapparatus 1B.

The units 2, 3, and 5 of the substrate processing apparatus 1B areconfigured and operate similarly to those of the units 2, 3, and 5 ofthe substrate processing apparatus 1 (1A). The nozzle moving mechanism 6of the substrate processing apparatus 1B, which is configured similarlyto the nozzle moving mechanism 6 of the substrate processing apparatus 1(1A), moves an object different from an object moved by the nozzlemoving mechanism 6 of the substrate processing apparatus 1 (1A). Thesubstrate processing apparatus 1B includes the surface protection unit4B in place of the surface protection unit 4 of the substrate processingapparatus 1 (1A) and includes the heating mechanism 7B in place of theheating mechanism 7 (7A) of the substrate processing apparatus 1 (1A).The substrate processing apparatus 1B further includes the rear surfaceprotection unit 8. The units 2, 3, and 5 of the substrate processingapparatus 1B will not be described here, and the units 4B, 6, 7B, and 8will now be described.

Surface Protection Unit 4B

The surface protection unit 4B includes a gas discharge mechanism (alsoreferred to as a “gas discharge mechanism for peripheral portion” or a“gas discharge unit”) 441 that discharges a gas flow of an inert gassuch that the gas flow comes into contact with the peripheral portion ofthe upper surface of the substrate W held and being rotated on the spinchuck 21. The gas discharge mechanism 441 discharges the inert gas as,for example, a gas-column-shaped gas flow G1.

The configuration and the like of the surface protection unit 4B, whichdiffer from those of the surface protection unit 4 of the substrateprocessing apparatus 1 (1A), will be described below. Description of asimilar configuration will be omitted appropriately. The components ofthe surface protection unit 4B, whose description will be omitted, canbe described in the description of the components bearing the samereference signs of the surface protection unit 4 described above, or canbe described in the description of the surface protection unit 4 byreplacing the reference signs of the components of the surfaceprotection unit 4 and the like with the reference sings of thecorresponding components of the surface protection unit 4B and the like.The corresponding components bear reference sings combining numerals ofthe surface protection unit 4 and an alphabet “B”.

The surface protection unit 4B further includes a gas dischargemechanism (also referred to as a “gas discharge mechanism for centralportion” or “another gas discharge unit”) 443. The gas dischargemechanism 443 is configured and operates similarly to the gas dischargemechanism 443 of the substrate processing apparatus 1 (1A). The surfaceprotection unit 4B discharges gas flows G1 and G3 of an inert gas ontothe upper surface of the substrate W respectively from the gas dischargemechanisms 441 and 443, thereby protecting the to-be-protected region(“device region”) S4 (FIG. 26) of the upper surface of the substrate Wfrom, for example, the processing liquid discharged so as to come intocontact with the annular processing region S3 (FIG. 26) defined in theperipheral portion of the upper surface of the substrate W.

The gas discharge mechanism 441 includes a nozzle head 48B. The gasdischarge mechanism 443 includes the nozzle head 49. The nozzle heads48B and 49 are attached to the distal ends of elongated arms 61 and 62of the nozzle moving mechanism 6. The arms 61 and 62 extend along thehorizontal plane. The nozzle moving mechanism 6 moves the arms 61 and 62to move the nozzle heads 48B and 49 between their processing positionsand retreat positions.

The nozzle head 48B includes a nozzle (“gas discharge nozzle forto-be-processed surface”) 41 and a holding member holding the nozzle 41.The holding member is configured similarly to the holding member in thenozzle head 48 of the substrate processing apparatus 1 (1A) and is alsosimilarly attached to the distal end of the arm 61 to hold the nozzle41. The upper end of the nozzle 41 is connected with a first end of thepipe 471. A second end of the pipe 471 is connected to the gas supplysource 451. At some midpoint in the pipe 471, a flow rate controller 481and an on/off valve 461 are provided sequentially from the gas supplysource 451 side.

Here, when the nozzle moving mechanism 6 arranges the nozzle head 48B atits processing position, the outlet of the nozzle 41 is opposed to apart of the rotation path (“first rotation path”) of the peripheralportion of the upper surface of the substrate W rotated by the rotaryholding mechanism 2.

With the nozzle head 48B arranged at the processing position, the nozzle41 is supplied with an inert gas (in the illustrated example, a nitrogen(N₂) gas) from the gas supply source 451. The nozzle 41 discharges thegas flow G1 of the supplied inert gas from above such that the gas flowG1 comes into contact with the position P3 defined in the rotation pathof the peripheral portion of the upper surface of the substrate W. Thenozzle 41 discharges the gas flow G1 through the outlet in apredetermined direction such that the gas flow G1 reaches the positionP3 and then flows from the position P3 toward the periphery of thesubstrate W.

A liquid flow L1 of a processing liquid discharged from a nozzle head 50of the processing unit 5 comes into contact with a position (“landingposition”, “first position”) PL1 (FIG. 26) defined in the rotation pathof the peripheral portion of the upper surface of the substrate W. Awidth D1 of the liquid flow L1 in the radial direction of the substrateW is, for example, 0.5 to 2.5 mm. The nozzle head 50 can selectivelydischarge the liquid flow L1 of the processing liquid from each of aplurality of nozzles 51 a to 51 d. The position PL1 slightly variesdepending on the arrangements of the nozzles 51 a to 51 d and thedirection in which the processing liquid is discharged. The position P3with which the gas flow G1 comes into contact is located upstream fromthe position P1 corresponding to any of the nozzles 51 a to 51 d in thedirection of rotation of the substrate W along the periphery of thesubstrate W.

That is to say, the gas discharge mechanism 441 discharges the gas flow(“first gas flow”) G1 of the inert gas from above toward the position P3upstream from the position PL1, with which the processing liquiddischarged from the processing unit 5 comes into contact, in thedirection of rotation of the substrate W along the circumferentialdirection of the substrate W in the rotation path of the peripheralportion of the substrate W. The gas discharge mechanism 441 dischargesthe gas flow G1 in a predetermined direction such that the dischargedgas flow G1 flows from the position P3 toward the periphery of thesubstrate W.

The nozzle head 49 of the substrate processing apparatus 1B isconfigured and operates similarly to the substrate processing apparatus1 (1A) described above. Flow rate control units 481 and 483 and the pipe471 and a pipe 473 of the substrate processing apparatus 1B areconfigured similarly to the flow rate control units 481 and 483 and thepipes 471 and 473 of the substrate processing apparatus 1 (1A). Thecontrol unit 130B controls the flow rate control units 481 and 483 andthe on/off valve 461 and an on/off valve 463 similarly to the controlunit 130 (130A) of the substrate processing apparatus 1 (1A) via a valvecontrol mechanism (not shown). The control unit 130B thus controls howthe gas flows G1 and G3 are respectively discharged from the nozzles 41and 43 (such as a discharge start timing, a discharge end timing, and adischarge flow rate).

How easily the residual processing liquid that remains on the uppersurface of the substrate W is blown off by the gas flow G1 variesdepending on the film quality of the surface of the substrate W. Of thehydrophobic film quality and the hydrophilic film quality, thehydrophobic film quality is less likely to blow off the residualprocessing liquid, and the hydrophilic film quality is more likely toblow off the residual processing liquid. Therefore, how the gas flow G1is discharged is preferably set in accordance with the film quality ofthe surface of the substrate W.

Nozzle Moving Mechanism 6

The nozzle moving mechanism 6 is a mechanism that moves the nozzle heads48B, 49, and 50 of the gas discharge mechanisms 441 and 443 and theprocessing liquid discharge mechanism 830 between their processingpositions and retreat positions.

The nozzle moving mechanism 6 of the substrate processing apparatus 1Bis configured similarly to the nozzle moving mechanism 6 of thesubstrate processing apparatus 1 (1A). The nozzle heads 48B, 49, and 50are attached to the distal end portions of the arms 61 to 63 of thenozzle moving mechanism 6. Drives 67 to 69 of the nozzle movingmechanism 6 respectively move the nozzle heads 48B, 49, and 50horizontally between their processing positions and their retreatpositions in accordance with the control of the control unit 130B.

When the nozzle head 48B is arranged at the processing position, theoutlet of the nozzle 41 is opposed to a part of the rotation path of theperipheral portion of the substrate W rotated by the rotary holdingmechanism 2. The processing positions and retreat positions of thenozzle head 49 and the nozzle holding member 50 of the substrateprocessing apparatus 1B are positions respectively similar to theprocessing positions and the retreat positions of the nozzle head 49 andthe nozzle holding member 50 of the substrate processing apparatus 1(1A).

The respective retreat positions of the nozzle heads 48B, 49, and 50 ofthe substrate processing apparatus 1B are positions similar to theirrespective retreat positions of the nozzle heads 48, 49, and 50 of thesubstrate processing apparatus 1 (1A).

The drives 67 to 69 are electrically connected to the control unit 130Band operate under the control of the control unit 130B. The control unit130B causes the nozzle moving mechanism 6 to arrange the nozzle heads48B and 50 at the processing positions in accordance with the presetsetup information such that the gas flow G1 and the liquid flow L1respectively come into contact with the positions P3 and PL1 in therotation path of the peripheral portion of the substrate W. Thepositions P3 and PL1 are adjusted by changing the setup information. Thecontrol unit 130B causes the nozzle moving mechanism 6 to arrange thenozzle head 49 at the processing position in accordance with the setupinformation such that the gas flow G3 comes into contact with the centeror its vicinity of the substrate W. That is to say, the control unit130B controls the positions of the nozzle heads 48B, 49, and 50.Specifically, the control unit 130 controls the positions of the nozzles41, 43, and 51 a to 51 d.

The liquid flow L1 of the processing liquid, which has been dischargedonto the position PL1 in the rotation path of the peripheral portion ofthe upper surface of the substrate W, moves in the circumferentialdirection of the substrate W while adhering to the processing region S3in the form of a liquid film. During the movement, the central angle ofthe circular arc, which connects the portion to which the liquid film ofthe processing liquid adheres and the position PL1 along the end face(“edge”) of the substrate W, becomes greater. The centrifugal force dueto the rotation of the substrate W acts on the liquid film of theprocessing liquid during the movement. Thus, approximately 80% of theprocessing liquid is drained out of the substrate W until the centralangle reaches 90°. This rate varies depending on, for example, therotational speed and film quality of the substrate W, and the volume andviscosity of the processing liquid discharged.

If the width of the processing region S3, that is, the width with whichthe etching process or any other process is intended to be performed is1 mm, the liquid flow L1 of the processing liquid is preferablydischarged so as to come into contact with the substrate W with a widthin the range of 0.5 mm from the periphery of the substrate W. In thiscase, to efficiently remove the residual processing liquid from thesubstrate W while restricting splashes that arrive at theto-be-protected region S4, the gas flow G1 is preferably discharged suchthat the center of the cross-section of the gas flow G1 of the inert gascomes into contact with the substrate W within the range of, forexample, 4 to 8 mm from the periphery of the substrate W. The width ofthe liquid film of the residual processing liquid that adheres to theperipheral portion of the substrate W normally spreads to be larger thanthe width of the liquid flow L1 of the processing liquid that comes intocontact with the position PL1. As described above, therefore, the widthof the gas flow G1 of the inert gas is preferably larger than the widthof the liquid flow L1 of the processing liquid that comes into contactwith the peripheral portion of the substrate W. Specifically, the widthof the gas flow G1 of the inert gas is preferably set to be, forexample, three to five times the width of the liquid flow L1. Theresidual processing liquid that adheres to the peripheral portion of thesubstrate W is thus efficiently drained out of the substrate W by thegas flow G1.

Heating Mechanism 7B

The heating mechanism 7B is provided below the peripheral portion of thelower surface of the substrate W. The heating mechanism 7B includes anannular heater 71B extending in the circumferential direction of thesubstrate W along the peripheral portion of the lower surface of thesubstrate W, a gas discharge mechanism (“shielding gas dischargemechanism”) 444, and an electric circuit (not shown) that supplies powerto the heater 71B in accordance with the control of the control unit130B. The heating mechanism 7B is configured similarly to the heatingmechanism 7A of the substrate processing apparatus 1A except for that itincludes the heater 71B in place of the heater 71A.

FIGS. 28 to 30 are schematic top views of the heater 71B of the heatingmechanism 7B. FIG. 28 illustrates a heating element 73B and a heatingflow path 74B of the heater 71A. FIG. 29 does not illustrate the heatingflow path 74B of FIG. 28 for easy viewing, and FIG. 30 does notillustrate the heating element 73B of FIG. 28. The heating element 73Bis illustrated as a region in which the heating element 73B is arranged(arrangement region). The heating flow path 74B is arranged below theheating element 73B. The heater 71B is configured similarly to theheater 71A of the heating mechanism 7A of the substrate processingapparatus 1A except for that it includes the heating element 73B and theheating flow path 74B in place of the heating element 73 and the heatingflow path 74 and that it has a recess 170 formed in the outer peripheralsurface S10 of the heater 71B.

FIGS. 18 and 19 are schematic cross-sectional views of the heater 71B ofthe heating mechanism 7B. FIG. 18 is a longitudinal cross-sectional viewof the heater 71B taken along the lines I-I and II-II of FIG. 28, andFIG. 19 is a longitudinal cross-sectional view of the heater 71B takenalong the lines and IV-IV of FIG. 28. As illustrated in FIGS. 18 and 19,the structure of each cross-section of the heater 71B taken along thesecutting lines is the same as the structure of each cross-section of theheater 71A taken along corresponding cutting lines in the heater 71A ofthe substrate processing apparatus 1A.

A configuration of the heating mechanism 7B different from that of theheating mechanism 7A will be mainly described below. Description of asimilar configuration will be omitted appropriately. The components ofthe heating mechanism 7B, whose description will be omitted, can bedescribed in the description of the components bearing the samereference sings of the heating mechanism 7A described above, or can bedescribed in the description of the heating mechanism 7A by replacingthe reference sings of the components of the heating mechanism 7A andthe like with the reference sings of the corresponding components of theheating mechanism 7B and the like. The corresponding components bearreference signs combining the same numerals and an alphabet “B”.

The heater 71B is arranged in a positional relationship similar to thatof the heater 71A of the substrate processing apparatus 1A relative tothe substrate W and the spin chuck 21, and is held similarly to theheater 71A. The heater 71B is movable upward and downward by a movingmechanism (not shown) between the processing position and the retreatposition similarly to the heater 71A. The heater 71B is supplied withpower while being arranged at the processing position, and then, theheater 71B generates heat to heat the peripheral portion of thesubstrate W.

The heater 71B (body portion 72) is an annular plate-shaped memberextending in the circumferential direction of the substrate W along theperipheral portion of the lower surface of the substrate W. The recess170 is formed in the outer peripheral surface S10 of the heater 71B. Therecess 170 is recessed from the outer peripheral surface S10 of the bodyportion 72 toward the center of the heater 71B (toward the rotation axisal). The recess 170 passes through the heater 71B vertically from theopposed surface S7 of the heater 71B to a surface (lower surface) S8opposite to the opposed surface S7.

The recess 170 has a bottom surface 171 and side surfaces 172 and 173.The bottom surface 171 and the side surfaces 172 and 173 are verticalplanes of approximately elongated shape extending from the opposedsurface S7 of the heater 71B to the surface S8 heater 71B. The normal ofthe bottom surface 171 is orthogonal to the rotation axis a1. The sidesurface 172 (173) extends from the end of the bottom surface 171downstream (upstream) in the direction of rotation of the substrate W tothe outer peripheral surface S10 of the heater 71B. The side surfaces172 and 173 are orthogonal to the bottom surface 171 and are parallel toeach other.

The recess 170 has an opening (“opposed-surface opening) 174 open to theopposed surface S7, an opening (“outer-peripheral-surface opening”) 175open to the outer peripheral surface of the heater 71B, and an opening176 open to the surface S8. The openings 174 to 176 each have arectangular shape. The opening 174 is opposed to the portion, which isadjacent to the position PL2 with which the liquid flow L2 of the rinseliquid discharged from the nozzle 55 comes into contact, of theperipheral portion of the to-be-protected surface of the substrate W.The upper edges (lower edges) of the bottom surface 171 and the sidesurfaces 172 and 173 form the periphery of the opening 174 (176). Theintersecting lines of the outer peripheral surface S10 of the heater 71Band the side surfaces 172 and 173 form the periphery of the opening 175.The openings 174, 175, and 176 are sequentially continuous with eachother and form one opening from the opposed surface S7 of the heater 71Bto the surface S8 via the outer peripheral surface S10. The recess 170accommodates a nozzle head 150 holding nozzles 45 and 55 of the rearsurface protection unit 8, and the respective outlets of the distal endportions of the nozzles 45 and 55 are opposed to the peripheral portionof the lower surface of the substrate W.

The heating element 73B is arranged below the annular portion of theopposed surface S7 of the heater 71B except for the outer peripheralportion and the inner peripheral portion of the opposed surface S7 (morespecifically, the annular-belt shaped portion except for the opening 174of the recess 170), over the entire annular (more specifically,annular-belt-shaped) arrangement region defined along the annularportion. The arrangement region for the heating element 73B is parallelto the lower surface of the substrate W and the opposed surface S7 ofthe heater 71B. Preferably, the substrate W is uniformly heated withease if the arrangement region for the heating element 73B is parallelto the lower surface of the substrate W. Inside the heater 71B, atemperature (not shown) is also arranged. The temperature sensormeasures the temperature of the heater 71B and transmits the measurementresult to the control unit 130B. The control unit 130B controls powersupply to the heating element 73B based on the measurement result.

The heating flow path 74B is arranged below the heating element 73Balong the heating element 73B. The respective portions of the heatingflow path 74B can be uniformly heated with ease if the heating flow path74B is arranged along the heating element 73B. Thus, the inert gasflowing through each part of the heating flow path 74B is uniformlyheated with ease.

The body portion 72 of the heater 71B includes, for example, a lowermember 72 a, a middle member 72 b, and an upper member 72 c layeredsequentially from below to above. The members 72 a to 72 c are annularplate-shaped members extending in the circumferential direction of thesubstrate W along the peripheral portion of the lower surface of thesubstrate W. The recess 170 is formed in a part of the body portion 72at the outer peripheral surface side. In the cross-sectional shapes ofthe respective members 72 a to 72 c taken along the horizontal plane, arectangular recess is formed that is recessed from the outer peripheriesof the respective members 72 a to 72 c toward the centers of therespective members 72 a to 72 c.

In the example illustrated in FIG. 30, the heating flow path 74B isrepeatedly arranged as follows: it makes approximately one loop aroundan inner peripheral surface S9 of the heater 71B in the circumferentialdirection, is then doubled back toward the outer peripheral surface S10of the heater 71B in the plane extending along the opposed surface S7,and makes approximately one loop around the heater 71B in the oppositedirection. Consequently, the heating flow path 74B is arranged acrossthe inner peripheral surface S9 of the heater 71B and the outerperipheral surface S10 of the heater 71B so as to make approximatelyfour loops by being doubled back every time it makes approximately oneloop in the circumferential direction around the inner peripheralsurface S9 of the heater 71B. The heating flow path 74B is formed exceptfor in the recess 170. The heating flow path 74B cuts across fourlocations of the longitudinal cross-section of the heater 71B in thecircumferential direction of the heater 71B. The four locations arearranged sequentially at intervals in the radial direction of the heater71B. The innermost (innermost peripheral) portion, that is, the portionwith the smallest diameter of the heating flow path 74 is, when seenthrough from above, arranged between the inner periphery of the heater71B and the inner periphery of the arrangement region for the heatingelement 73 along both of the inner peripheries. The outermost (outermostperipheral) portion, that is, the portion with the largest diameter ofthe heating flow path 74 is, when seen through from above, arrangedbetween the outer periphery of the arrangement region for the heatingelement 73 and the outer periphery of the heater 71B along both of theouter peripheries.

The control unit 130B controls how the heater 71B heats the substrate Wand the inert gas (such as the temperature of the substrate W and thetemperature of the discharged inert gas) and also controls the positionof the heater 71B.

Rear Surface Protection Unit 8

The rear surface protection unit 8 includes a rinse liquid dischargemechanism 840 and a gas discharge mechanism 445. The rinse liquiddischarge mechanism 840 discharges a liquid flow L2 of a rinse liquidsuch that the liquid flow L2 comes into contact with the peripheralportion of the lower surface of the substrate W held and being rotatedon the spin chuck 21. The gas discharge mechanism 445 discharges a gasflow G5 of an inert gas such that the gas flow G5 comes into contactwith the peripheral portion.

The rear surface protection unit 8 discharges the liquid flow L2 of therinse liquid onto the peripheral portion of the lower surface of thesubstrate W from the rinse liquid discharge mechanism 840. By so doing,the rear surface protection unit 8 protects the lower surface of thesubstrate W from, for example, a processing liquid discharged so as tocome into contact with the position PL1 in the rotation path of theperipheral portion of the upper surface (more specifically, theprocessing region S3 of the peripheral portion of the upper surface) ofthe substrate W. The liquid flow L2 is discharged so as to come intocontact with the position (“second position”) PL2 defined in therotation path (“second rotation path”) of the peripheral portion of thelower surface. The position PL2 is determined to be upstream from theposition PL1 in the direction of rotation of the substrate W.

The rear surface protection unit 8 discharges the gas flow G5 of theinert gas onto the peripheral portion of the lower surface of thesubstrate W from the gas discharge mechanism 445. The gas flow G5 isdischarged so as to come into contact with the position (“fourthposition”) P4 in the rotation path of the peripheral portion of thelower surface and flow from the position P4 toward the periphery of thelower surface of the substrate W. The position P4 is determined to beupstream from the position PL2 in the direction of rotation of thesubstrate W. A part of the liquid flow L2 of the rinse liquid dischargedonto the position PL2 loops in the circumferential direction of thesubstrate W while and remaining in the peripheral portion of the lowersurface of the substrate W in the form of a liquid film. Most of theresidual rinse liquid is blown off by the gas flow G5 to be drained outof the substrate W from the peripheral portion of the lower surface ofthe substrate W. This restricts mixing of a rinse liquid newlydischarged from the rinse liquid discharge mechanism 840 onto theposition PL2 and the residual rinse liquid to excessively increase thevolume of the rinse liquid.

The rinse liquid discharge mechanism 840 includes a tubular nozzle(“rinse liquid discharge nozzle”) 55. The nozzle 55 passes through thenozzle head 150 and is held by the nozzle head 150. The nozzle head 150has an approximately rectangular-solid-shaped outer appearance. Thenozzle head 150 is accommodated in the recess 170 of the heater 71B soas to be arranged below the peripheral portion of the lower surface(portions adjacent to the position PL2 and the position P4) of thesubstrate W, with its upper surface being horizontal. The heater 71B isarranged in advance such that the recess 170 is located below theportions adjacent to the position PL2 and the position P4. The nozzlehead 150 is held by, for example, a support member (not shown) providedin the casing 24. The nozzle 55 is connected with a rinse liquid supplyunit 84 serving as a pipe system that supplies a rinse liquid to thenozzle 55. Specifically, the lower end of the nozzle 55 is connectedwith a first end of a pipe 842 of the rinse liquid supply unit 84. Theoutlet of the distal end of the nozzle 55 is opposed to the positionPL2. The nozzle 55 is supplied with a rinse liquid from the rinse liquidsupply unit 84 and discharges the supplied rinse liquid through theoutlet of the distal end. The rinse liquid discharge mechanism 840discharges the liquid flow L2 of the rinse liquid from the nozzle 55 inaccordance with the control of the control unit 130B. The liquid flow L2is discharged so as to come into contact with the position PL2 definedin the rotation path of the peripheral portion of the lower surface ofthe substrate W.

The rinse liquid supply unit 84 specifically includes a rinse liquidsupply source 841, the pipe 842, and an on/off valve 843. The rinseliquid supply source 841 is a supply source that supplies a rinseliquid. The rinse liquid supply source 841 is connected to the nozzle 55via the pipe 842 in which the on/off valve 843 is interposed. When theon/off valve 843 is opened, thus, the rinse liquid supplied from therinse liquid supply source 841 is discharged from the nozzle 55 onto theposition PL2 as the liquid flow L2.

The on/off valve 843 of the rinse liquid supply unit 84 is opened orclosed under the control of the control unit 130B by a valve open/closemechanism (not shown) electrically connected to the control unit 130B.That is to say, the control unit 130B controls how the rinse liquid isdischarged from the nozzle 55 of the nozzle head 150 (such as adischarge start timing, a discharge end timing, and a discharge flowrate). Specifically, by the control of the control unit 130B, the rinseliquid discharge mechanism 840 discharges the liquid flow L2 of therinse liquid such that the liquid flow L2 comes into contact with theposition PL2 in the rotation path of the lower peripheral portion of thesubstrate W being rotated about the rotation axis a1.

The gas discharge mechanism 441 includes a nozzle (“gas charge nozzlefor to-be-protected surface”) 45. The nozzle 45 passes through thenozzle head 150 and is held by the nozzle head 150 on the side upstreamfrom the nozzle 55 in the direction of rotation of the substrate W. Thelower end of the nozzle 45 is connected with a first end of the pipe475. A second end of the pipe 475 is connected with the gas supplysource 455 that supplies an inert gas. At some midpoint in the pipe 475,a flow rate control unit 485 and an on/off valve 465 are providedsequentially from the gas supply source 455 side. The outlet of thedistal end (upper end) of the nozzle 45 is opposed to the part of therotation path of the peripheral portion of the lower surface of thesubstrate W rotated by the rotary holding mechanism 2, specifically, theposition P4 determined in the rotation path.

The nozzle 45 is supplied with an inert gas (in the illustrated example,a nitrogen (N₂) gas) from the gas supply source 455. The nozzle 45discharges the gas flow G5 of the supplied inert gas from below suchthat the gas flow G5 comes into contact with the position P4. The nozzle45 discharges the gas flow G5 through the outlet in a predetermineddirection such that the discharged gas flow G5 arrives at the positionP4 and then flows from the position P4 toward the periphery of thesubstrate W.

The flow rate control unit 485 includes a flowmeter and a variablevalve. The flowmeter detects the flow rate of a gas flowing through thepipe 475. The variable valve can adjust the flow rate of the gas inaccordance with an open/close amount of the valve. The control unit 130Bcontrols an open/close amount of the variable valve of the flow ratecontrol unit 485 via a valve control mechanism (not shown) such that theflow rate detected by the flowmeter of the flow rate control unit 485 isequal to a target flow rate. The control unit 130B can set a target flowrate within a predetermined range in accordance with the preset setupinformation to freely control a flow rate of a gas passing through theflow rate control unit 485 within the predetermined range. The controlunit 130B also controls the on/off valve 465 between the open state andthe closed state via the valve control mechanism. The control unit 130Bthus controls how the gas flow G5 is discharged from the nozzle 45 (suchas a discharge start timing, a discharge end timing, and a dischargeflow rate).

How easily the residual rinse liquid is blown off by the gas flow G5varies depending on the film quality of the surface of the substrate W.Of the hydrophobic film quality and the hydrophilic film quality, thehydrophobic film quality is less likely to blow off the residualprocessing liquid, and the hydrophilic film quality is more likely toblow off the residual processing liquid. Therefore, how the gas flow G5is discharged is preferably set in accordance with the film quality ofthe surface of the substrate W.

3-2. Actions of Rinse Liquid Discharged onto Lower Surface and Inert GasDischarged onto Upper and Lower Surfaces

As illustrated in FIGS. 26 and 27, one (in the illustrated example, thenozzle 51 c) among the nozzles 51 a to 51 c capable of discharging achemical solution as a processing liquid discharges the liquid flow L1of the chemical solution such that the liquid flow L1 comes into contactwith the position PL1 in the rotation path of the peripheral portion ofthe upper surface of the substrate W. The nozzle 55 of the rinse liquiddischarge mechanism 840 discharges the liquid flow L2 of the rinseliquid such that the liquid flow L2 comes into contact with the positionPL2 in the rotation path of the peripheral portion of the lower surface(to-be-protected surface) opposite to the upper surface (to-be-processedsurface) of the substrate W. The position PL2 is a position upstreamfrom the position PL1 in the direction of rotation of the substrate W.

The nozzle 41 of the gas discharge mechanism 441 discharges the gas flowG1 of the inert gas such that the gas flow G1 comes into contact withthe position (“third position”) P3 in the rotation path of theperipheral portion of the upper surface of the substrate W. The positionP3 is located between the position PL1 and the position PL2 along theperiphery (end face S5) of the substrate W.

The nozzle 45 of the gas discharge mechanism 445 discharges the gas flowG5 of the inert gas such that the gas flow G5 comes into contact withthe position P4 in the rotation path of the peripheral portion of thelower surface of the substrate W. The position P4 is located adjacent tothe position PL2 upstream from the position PL2 in the direction ofrotation of the substrate W.

FIG. 34 is a longitudinal cross-sectional view of the substrate Wschematically illustrating how the liquid flow L2 of the rinse liquiddischarged by the substrate processing apparatus 1B wraps around an endface S5 of the substrate. The longitudinal cross-sectional view of thesubstrate W of FIG. 34 is a cross-sectional view of the substrate W cuton the cutting surface including the rotation axis a1 and the positionPL1. The liquid flow L1 of the chemical solution, the liquid flow L2 ofthe rinse liquid, and the gas flow G1 of the inert gas are projectedonto the cutting surface and illustrated schematically. Although theliquid flows L1 and L2 and the gas flow G1 discharged onto the surfaceof the substrate W flow along the surface of the substrate W, for easyviewing, FIG. 34 illustrates these flows at intervals from the surfaceof the substrate W.

The flat portion of the upper surface and the flat portion of the lowersurface of the substrate W are connected by an annular curved surfaceS30 provided along the circumferential direction of the substrate W. Ifa depth D11 of the substrate W is, for example, 0.7 mm, a width D12 ofthe curved surface S30 along the radial direction of the substrate W is,for example, 0.3 mm. In the longitudinal cross-section of the substrateW, the curved surface S30 projects toward the outside of the substrate Walong the radial direction of the substrate W and is curved. The annularapex (distal end portion) of the curved surface S30 is an end face (alsoreferred to as a “periphery” or “edge”) S5 of the substrate W. A curvedsurface portion S3 a is a portion of the curved surface S30 on the sideclose to the upper side (on the side close to the to-be-processedsurface) relative to the end face S5. The curved surface portion S3 a isan annular curved surface connecting a flat portion S3 b and the endface S5. The processing region S3 of the peripheral portion of the uppersurface of the substrate W on the side closer to the periphery includesthe annular flat portion S3 b and the annular curved surface portion S3a.

The liquid flow L2 of the rinse liquid discharged onto the position PL2loops in the circumferential direction of the substrate W along theperipheral portion of the lower surface of the substrate W due to theinfluence of, for example, the direction in which the liquid flow L2 isdischarged and the rotation of the substrate W, and a part of the rinseliquid wraps around the curved surface S30 of the substrate W includingthe end face S5 from the peripheral portion of the lower surface of thesubstrate W. Here, although a part of the liquid flow L2 wraps aroundthe end face S5 and the curved surface portion S3 a of the substratefrom the to-be-protected surface of the substrate W when the liquid flowL2 moves from the position PL2 in the circumferential direction of thesubstrate W and then arrives at the position PL1 or its vicinity (belowthe position PL1), the position PL2 (a distance from the position PL2 tothe position PL1 along the periphery of the substrate W) is set inadvance relative to the position PL1 such that the part of the liquidflow L2 does not wrap around up to the flat portion S3 b. Specifically,the position PL2 is set in advance such that a part of the liquid flowL2 of the rinse liquid wraps around the end face S5 of the substrate Wfrom the to-be-protected surface of the substrate W and hardly wrapsaround the peripheral portion of the to-be-processed surface. Theposition PL2 described above varies depending on the conditions fordischarging the rinse liquid, such as the rotational speed and thesurface film quality of the substrate W, and the viscosity and flow rateof the liquid flow L2. The position PL2 is set in advance throughexperiments or the like in accordance with the conditions fordischarging the rinse liquid.

When the liquid flow L1 of the chemical solution is discharged onto theposition PL1, the liquid flow L1 moves in the circumferential directionof the substrate W along with the rotation of the substrate W. Also, apart of the liquid flow L1 wraps around the curved surface portion S3 afrom the flat portion S3 b of the substrate W. The position PL2,however, is set such that the rinse liquid that has been discharged ontothe position PL2 and wrapped around the end face S5 hardly wraps aroundthe peripheral portion of the upper surface, thus restricting thedilution of the processing liquid discharged onto the position PL1 withthe rinse liquid on the peripheral portion of the upper surface. Also,the gas flow G1 of the inert gas discharged onto the position P3 canfurther restrict the rinse liquid from wrapping around the peripheralportion of the upper surface.

A part of the processing liquid discharged onto the position PL1 turnsinto the residual processing liquid remaining on the peripheral portionof the upper surface and wraps around up to the position P3. At theposition P3, the gas flow G1 blows off most of the residual processingliquid to drain the residual processing liquid out of the substrate W.This restricts the generation of splashes due to a collision between theresidual processing liquid and a processing liquid newly discharged ontothe position PL1.

Before the rinse liquid discharged onto the position PL1 arrives at theposition PL1 or its vicinity, a part of the rinse liquid has wrappedaround the end face S5. This restricts the processing liquid dischargedonto the position PL1 from wrapping around the peripheral portion of thelower surface of the substrate W via the end face S5.

A part of the rinse liquid discharged onto the position PL2 turns intothe liquid-film-shaped residual rinse liquid adhering to and remainingat the peripheral portion of the lower surface of the substrate W, andthen loops by the rotation of the substrate W to arrive at the positionP4 or its vicinity. The gas flow G5 of the inert gas discharged onto theposition P4 blows off most of the residual rinse liquid to drain theresidual rinse liquid out of the substrate W. This restricts a situationin which the residual rinse liquid and a rinse liquid newly dischargedonto the position are mixed to excessively increase the volume of therinse liquid, and accordingly, the rinse liquid wraps around the uppersurface of the substrate W.

The heater 71B has the recess 170 formed therein, and the recess 170 hasthe opening 174 that is opposed to the portions adjacent to thepositions PL2 and P4 in the rotation path of the peripheral portion ofthe lower surface of the substrate W and that is open to the opposedsurface S7. At least the outlets of the nozzles 45 and 55 of the rinseliquid discharge mechanism 840 are accommodated in the recess 170. Theoutlet of the distal end portion of the nozzle 55 (45) is arranged inthe opening 174 when the recess 170 is viewed from the opening 174 side.This enables the nozzle 55 and the nozzle 45 having simpleconfigurations to easily perform the following operationssimultaneously: heating the peripheral portion of the substrate W by theheater 71B and discharging the liquid flow L2 of the rinse liquid andthe gas flow G5 of the inert gas onto the peripheral portion of thelower surface of the substrate W.

3-3. Another Example of Heater

FIG. 32 (FIG. 33) is a schematic perspective view of a heater 71X (71Y)that is another example of the heater 71B, as viewed from diagonallyabove. The heater 71X (71 Y) is configured similarly to the heater 71Bexcept for that a recess 170X (170Y) is formed in place of the recess170 of the heater 71B (71 Y).

Unlike the recess 170 of the heater 71B, the recess 170X of the heater71X does not pass through the heater 71X vertically. An opening 175X ofthe heater 71X that is open to the outer peripheral surface S10 is thusopen across the outer peripheral surface S10 from the upper end of theouter peripheral surface S10 to the center and its vicinity of the outerperipheral surface S10. Like the recess 170X of the heater 71X, therecess 170Y of the heater 71Y does not pass through the heater 71Yvertically. The recess 170X differs from the recess 170Y in that therecess 170X has the opening 175X open to the outer peripheral surfaceS10, whereas the recess 170Y is not open to the outer peripheral surfaceS10. An opening 174Y that is open to the opposed surface S7 of theheater 71 Y is open to the outer-periphery-side portion of the annularopposed surface S7. The opening 174Y, however, does not extend up to theouter periphery of the opposed surface S7 along the radial direction ofthe heater 71 Y.

If the nozzle head 150 holding the nozzles 45 and 55 are accommodated inthe recess 170X (170Y) such that the outlets of the nozzles 45 and 55are opposed to the positions P4 and PL2, the following operations can beperformed simultaneously: heating the peripheral portion of thesubstrate W by the heater 71 X (71 Y), and discharging the liquid flowL2 of the rinse liquid and the gas flow G5 of the inert gas onto theperipheral portion of the lower surface of the substrate W. Thus, theheater 71X (71Y) may be employed in place of the heater 71B.Alternatively, the recess 170Y of the heater 71Y may pass through theheater 71 Y vertically.

3-4. Action of Shielding Gas

FIG. 20 illustrates an example of the gas flow G4 of the inert gasdischarged between the heater 71B and the substrate. The heater 71Birradiates the lower surface of the substrate W with rays of heat H1from the opposed surface S7 through heat generation of the heatingelement 73B, thereby heating the substrate W. The inert gas supplied bythe gas discharge mechanism 444 is introduced into the heating flow path74B and is preheated by the heating element 73B while flowing throughthe heating flow path 74B. The heated gas passes through the throughholes 76 and 77 and is then discharged into the space V1 through theoutlets 78 and 79 as the gas flow G4 of the inert gas.

The gas flow G4 flows toward the periphery of the substrate W and thecenter of the substrate W from each of the outlets 78 and 79. On theside close to the periphery of the substrate W and the side close to thesubstrate W relative to the heater 71B, an atmosphere G9 of temperaturelower than that of the heated gas flow G4 is present. The gas flow G4discharged through the outlet 78 and directed toward the periphery ofthe substrate W restricts the atmosphere G9, which is present on theside close to the periphery of the substrate W relative to the heater71B, from wrapping around the space V1. The gas flow G4 dischargedthrough the outlet 79 and directed toward the center of the substrate Wrestricts the atmosphere G9, which is present on the side close to thecenter of the substrate W relative to the heater 71B, from wrappingaround the space V1. This restricts a reduction in the heatingefficiency of the substrate W by the heater 71B due to the atmosphereG9. Also, the gas flow G4 is preheated, thus contributing to heating ofthe substrate W.

The inert gas discharged by the gas discharge mechanism 441 serves as ashielding gas that prevents the atmosphere G9 from entering the space V1and also as a heating gas that heats the substrate W.

When the liquid flow L2 of the rinse liquid and the gas flow G5 of theinert gas that are respectively discharged onto the positions PL2 and P4from the nozzles 55 and 45 enter the space V1 between the heater 71B andthe lower surface of the substrate W, the heating efficiency of theperipheral portion of the substrate W by the heater 71B may decrease dueto scattering of the rinse liquid onto the opposed surface S7 of theheater 71B. Thus, the position PL2 and the position P4 are preferablyprovided on the side closer to the periphery of the substrate W than theoutlet 78 through which an inert gas is discharged from the outerperipheral portion of the opposed surface S7 of the heater 71B. Thisenables the use of the inert gas discharged from the gas dischargemechanism 444 as a shielding gas that prevents the rinse liquid or anunheated inert gas from entering the space V1.

3-5. Operation of Substrate Processing Apparatus

FIG. 31 is a flowchart illustrating an example operation in which thesubstrate processing apparatus 1B processes a substrate with aprocessing liquid. The operation of the substrate processing apparatus1B will be described below with reference to FIG. 31. Before theoperation illustrated in FIG. 31, the substrate W has been transferredto the substrate processing apparatus 1B to be held on the spin chuck21. The nozzle heads 48B, 49, and 50 have been arranged at theprocessing positions by the nozzle moving mechanism 6, and the splashguard 31 has been arranged at the upper position by the guard drivemechanism 32.

When the process illustrated in FIG. 31 is started, the rotatingmechanism 231 of the substrate processing apparatus 1B starts rotatingthe spin chuck 21 holding the substrate W (step S310). The rotationalspeed of the substrate W is set to, for example, 1000 rotations perminute.

Then, the gas discharge mechanism 441 starts discharging the gas flowsG1 of the inert gas from the nozzle 41 of the nozzle head 48B, and thegas discharge mechanism 443 starts discharging the gas flow G3 of theinert gas from the nozzle 43 of the nozzle head 49, and the gasdischarge mechanism 445 starts discharging the gas flow G5 of the inertgas from the nozzle 45 (step S320). The gas flows G1 and G5 arerespectively discharged onto the position P3 on the peripheral portionof the upper surface of the substrate W and the position P4 on theperipheral portion of the lower surface of the substrate W. Preferably,the gas flows G1 and G5 are respectively discharged in predetermineddirections so as to come into contact with the positions P3 and P4 andthen flow toward the periphery of the upper surface and the periphery ofthe lower surface. The nozzle 43 discharges the inert gas from aboveonto the central portion of the upper surface of the substrate W togenerate the gas flow G3 spreading from the central portion toward theperiphery of the substrate W. The flow rate of the gas flow G3 when thegas flow G3 discharged from the nozzle 43 is discharged is higher thanthe flow rate when the gas flow G1 is discharged.

After the discharge of the gas flows G1 and G3 has been started, theheating mechanism 7B starts heating the peripheral portion of thesubstrate W by the heater 71B. The heater 71B is heated to, for example,approximately 185°. The gas discharge mechanism 444 of the heatingmechanism 7B starts supplying the inert gas from the gas supply source454 at a flow rate of, for example, 40 L/min to 60 L/min to startdischarging the gas flow G4 through the plurality of outlets 78 and 79formed in the opposed surface S7 of the heater 71B (step S330). Theinert gas is heated to be higher than the processing temperature (e.g.,60° C. to 90° C.) of the substrate W.

After the temperature of the peripheral portion of the substrate W hasrisen and become stable after a lapse of time, the rinse liquiddischarge mechanism 840 starts discharging the liquid flow L2 of therinse liquid such that the liquid flow L2 comes into contact with theposition PL2 determined in the rotation path of the peripheral portionof the lower surface of the substrate W (step S340). The liquid flow L2is preferably discharged in a predetermined direction such that theliquid flow L2, which has come into contact with the position PL2, flowsalso from the position PL2 toward the periphery of the lower surface ofthe substrate W.

The processing liquid discharge mechanism 830 discharges the liquid flowL1 of the processing liquid (chemical solution) such that the liquidflow L1 comes into contact with the position PL1 determined in therotation path of the peripheral portion of the upper surface of thesubstrate W (more specifically, the processing region S3 of the uppersurface on the side closer to the end face S5 of the substrate W) afterthe rinse liquid discharged first onto the position PL2 arrives at belowthe position PL1, thereby processing the peripheral portion of the uppersurface (step S350). Specifically, the processing liquid dischargemechanism 830 discharges the liquid flow L1 of the chemical solutionfrom one nozzle (in FIG. 23, the nozzle 51 c) among the nozzles 51 a to51 d in accordance with the control of the control unit 130B. Thecross-sectional size and flow rate of the liquid flow L1 are set inadvance such that the width of the liquid film, which turns from theliquid flow L1 and adheres to the peripheral portion of the substrate W,fits in the processing region S3. The liquid flow L1 comes into contactwith the position PL1 and then forms a liquid film on the processingregion S3. The liquid film of the processing liquid moves in thecircumferential direction of the substrate W while adhering to theperipheral portion of the substrate W along with the rotation of thesubstrate W.

A part of the processing liquid discharged onto the position PL1 flowsfrom the peripheral portion of the upper surface of the substrate Wthrough the end face S5 of the substrate W to begin to wrap around theperipheral portion of the lower surface. A part of the liquid flow L2 ofthe rinse liquid, however, wraps around the end face S5 after beingdischarged onto the position PL2. Thus, the rinse liquid that haswrapped around the end face S5 restricts the processing liquid fromwrapping around the lower surface of the substrate W.

From the viewpoint of improving the processing rate of the substrate W,the discharged processing liquid preferably stays at the position ofdischarge in the processing region S3 for the longest possible period oftime. The central angle, which is formed between the straight lineconnecting the position PL1 in the rotation path and the center c1 ofthe substrate W and the straight line connecting the portion onto whichthe liquid flow L1 has been discharged and the center c1, graduallyincreases along with the rotation of the substrate W. For example, 80%of the processing liquid discharged onto the processing region S3 isdrained out of the substrate W mainly by the centrifugal forceassociated with the rotation of the substrate W while the substrate Wrotates until the central angle reaches 90°. After that, theliquid-film-shaped processing liquid that has not been drained out andhas remained in the substrate W also moves along the circumferentialdirection of the substrate W while being gradually drained out of thesubstrate W and simultaneously adhering to the processing region S3,thus contributing to processing of the substrate W during the process.

The gas flow G1, whose discharge has been started from the nozzle 41 instep S310, comes into contact with the liquid film of the residualprocessing liquid at the position P3. The position P3 is locatedupstream from the position PL1 in the direction of rotation of thesubstrate W along the circumferential direction of the substrate W inthe rotation path of the substrate W, and is also located downstreamfrom the position PL2 in the direction of rotation. Subsequently, thegas flow G1 flows from the position P3 toward the periphery of thesubstrate W due to the influence of, for example, the direction in whichthe gas flow G1 flows and the rotation of the substrate W. In otherwords, the gas discharge mechanism 441 discharges the gas flow G1 of theinert gas from above onto the position P3 in the rotation path of theperipheral portion of the upper surface of the substrate W, therebydirecting the gas flow G1 from the position P3 toward the periphery ofthe substrate W. Most of the residual processing liquid is drained outof the substrate W from the peripheral portion of the upper surface ofthe substrate W by the gas flow G1.

The gas flow G3 discharged from the nozzle 43 of the gas dischargemechanism 443 spreads from the central portion of the substrate W towardthe periphery of the substrate W due to the influence of, for example,the direction in which the gas flow G3 is discharged and the rotation ofthe substrate W. In other words, the gas discharge mechanism 443discharges the inert gas from above the central portion of the uppersurface of the substrate W to generate the gas flow G3 spreading fromthe central portion toward the periphery of the substrate W.

The rinse liquid discharged onto the position PL2 flows to below theposition PL1 along the periphery of the substrate W, and while theflowing, a part of the rinse liquid wraps around the end face S5 of thesubstrate W from the peripheral portion of the lower surface of thesubstrate W. The rinse liquid that has wrapped around the end face S5 isrestricted from wrapping around the upper surface of the substrate W bythe gas flow G1 flowing from the position P3 toward the periphery of thesubstrate W. Also, although a part of the rinse liquid discharged ontothe position PL2 turns into a residual rinse liquid that adheres to andremains in the peripheral portion of the lower surface of the substrateW and makes loops on the lower surface of the substrate W, most of theresidual rinse liquid is blown off by the gas flow G5 of the inert gasdischarged onto the position P4 to be drained out of the substrate W.This restricts mixing of the residual rinse liquid and a rinse liquidnewly discharged onto the position PL2 to excessively increase thevolume of the rinse liquid.

As described above, most of the processing liquid discharged at theposition PL1 so as to come into contact with the processing region S3 ofthe substrate W is drained out of the substrate W during one rotation ofthe substrate W. This restricts the splashes generated due to aprocessing liquid newly discharged onto the position PL1 from cominginto contact with the residual processing liquid. The rinse liquid isalso restricted from wrapping around the upper surface of the substrateW, thus restricting the dilution of the processing liquid dischargedonto the position PL2 with the rinse liquid that has wrapped around theupper surface. Also, the rinse liquid that has wrapped around the endface S5 of the substrate W restricts the processing liquid from wrappingaround the lower surface of the substrate W. Also, the residual rinseliquid can be easily drained out of the substrate W by the gas flow G5discharged onto the position P4.

While discharging of the gas flows G1, G3, and G5 and discharging of theliquid flow L1 are performed simultaneously, the rotating mechanism 231rotates the substrate W repeatedly in accordance with the control of thecontrol unit 130B. For example, the gas flows G1, G3, and G5 aredischarged respectively at flow rates of 12 L/min, 30 L/min to 130L/min, and 10 L/min to 10 to 20 L/min.

When the control unit 130B detects, for example, a lapse of a processingtime required for processing the substrate W, the processing liquiddischarge mechanism 830 stops discharging the processing liquid. Thiscompletes the process of step S340.

The rinse liquid discharge mechanism 840 stops discharging the liquidflow L2 of the rinse liquid onto the lower surface (position PL2) of thesubstrate W (step S360). The heating mechanism 7B stops power supply tothe heater 71B to stop heating the substrate W by the heater 71B andalso stops discharging the gas flow G4 by the gas discharge mechanism444 (step S370).

The rotating mechanism 231 stops rotating the spin chuck 21 (step S380),and the heating mechanism 7B stops heating the peripheral portion of thesubstrate W by the heater 71B. The gas discharge mechanisms 441, 443,and 445 respectively stop discharging the gas flows G1, G3, and G5 (stepS390). As a result, the operation illustrated in FIG. 31 ends.

After that, the nozzle moving mechanism 6 and the guard drive mechanism32 respectively move the nozzle heads 48B, 49, and 50, and the splashguard 31 to the retreat positions. The substrate W is removed from thespin chuck 21 to be transferred from the substrate processing apparatus1B.

The substrate processing apparatus 1B discharges the chemical solutionsuch that the chemical solution comes into contact with the position PL1in the rotation path of the peripheral portion of the upper surface(to-be-processed surface) of the substrate W and discharges the rinseliquid such that the rinse liquid comes into contact with the positionPL2 in the rotation path of the peripheral portion of the lower surface(to-be-protected surface) opposite to the upper surface of the substrateW. The position PL2 is located upstream from the position PL1 in thedirection of rotation of the substrate W. The heater 71B opposed to thelower surface of the substrate W heats the substrate W from the lowersurface of the substrate W. The gas discharge mechanism 444 dischargesthe gas flow G4 of the heated inert gas into the space V1 between theopposed surface S7 of the heater 71B and the lower surface of thesubstrate W. Alternatively, the to-be-processed surface may be the lowersurface of the substrate W. In other words, the nozzles of theprocessing liquid discharge mechanism 830 may discharge the chemicalsolution such that the chemical solution comes into contact with thefirst position in the rotation path of the peripheral portion of thelower surface of the substrate W. The nozzle 55 of the rinse liquiddischarge mechanism 840 may discharge the rinse liquid such that therinse liquid comes into contact with the second position in the rotationpath of the upper surface of the substrate W. The second position may belocated upstream from the first position in the direction of rotation ofthe substrate W. In this case, the heater 71B heats the substrate Wwhile being opposed to the upper surface of the substrate W, and the gasdischarge mechanism 444 discharges the gas flow G4 into the spacebetween the upper surface of the substrate W and the lower surface(opposed surface) of the heater 71B. The rinse liquid discharged ontothe position PL2 of the upper surface wraps around the lower surfacethat is a to-be-processed surface more easily than in the case in whichthe to-be-processed surface is the upper surface. The volume of therinse liquid is thus adjusted in advance.

The substrate processing apparatus 1B may be devoid of at least one gasdischarge mechanism of the gas discharge mechanism 441 that dischargesthe gas flow G1 of the inert gas onto the position P3 and the gasdischarge mechanism 445 that discharges the gas flow G5 of the inert gasonto the position P4.

Although the rinse liquid discharge mechanism 840 includes one nozzle55, the rinse liquid discharge mechanism 840 may include a plurality ofnozzles 55 distributed sparsely in the circumferential direction of thesubstrate W and discharge, from the plurality of nozzles 55, the rinseliquid onto a plurality of positions PL2 determined in the rotation pathof the peripheral portion of the to-be-protected surface of thesubstrate W. If the rinse liquid discharge mechanism 840 includes aplurality of nozzles 55, it can protect the to-be-protected surface ofthe substrate more uniformly.

Although the gas discharge mechanism 445 includes one nozzle 45, the gasdischarge mechanism 445 may include a plurality of nozzles 45 anddischarge, from the plurality of nozzles 45, an inert gas onto aplurality of positions P4 determined in the rotation path of theperipheral portion of the to-be-protected surface of the substrate W.The plurality of positions P4 are determined on the side upstream fromthe position PL2 in the direction of rotation of the substrate W.

The gas discharge mechanism 441 discharges, from one nozzle 41, the gasflow G1 of the inert gas onto the position P3 in the rotation path ofthe peripheral portion of the upper surface of the substrate W, wherethe position P3 is determined between the position PL2 and the positionPL1 along the peripheral portion of the substrate W. Alternatively, thegas discharge mechanism 444 may discharge, from a plurality of nozzles41, the gas flow G1 of the inert gas onto a plurality of positions P3 inthe rotation path of the peripheral portion of the upper surface. Theplurality of positions P3 are determined between the position PL2 andthe position PL1 along the peripheral portion of the substrate W.

The gas discharge mechanism 444 discharges the gas flow G4 from aplurality of outlets 78 and 79 provided in the heater 71B, while thesubstrate W rotates. The gas discharge mechanism 444 may thus dischargethe gas flow G4 from a single outlet 78 and a single outlet 79 providedin the heater 71B. Even when the gas flow G4 is discharged through onlyone outlet of the outlet 78 and the outlet 79, a temperature drop of thesubstrate W can be restricted more than in the case in which the gasflow G4 is not discharged. Alternatively, a flow path for the inert gasmay be provided between the opposed surface S7 of the heater 71B and theheating element 73B such that the gas flow G4 may be discharged throughan outlet open to above the heating element 73B.

The gas discharge mechanism 444 may discharge the inert gas preheatedby, for example, another heater different from the heater 71B into thespace V1. Specifically, the gas discharge mechanism 444 may preheat theinert gas supplied from the gas supply source 454 by the other heaterand, through the pipe outside of the heater 71B, discharge the heatedinert gas into the space V1 from the nozzle outside of the heater 71B.

The heater 71B may be provided so as to cover the entire surface, whichis opposite to the to-be-processed surface, of the substrate W. Such aheater 71B can be provided between the lower surface of the substrate Wand the upper surface of the spin chuck 21 when the spin chuck 21, whichincludes a plurality of chuck pins, holds the substrate W such that thesubstrate W does not contact the upper surface of the spin chuck 21. Inthis case, the heater 71B is supported by a columnar support memberpassing through the inside of the rotary shaft 22 and the spin chuck 21.

Although the substrate processing apparatus 1B includes the nozzle 43that discharges the gas flow G3 of the inert gas, the substrateprocessing apparatus 1B may include no nozzle 43. In that case, thesubstrate processing apparatus 1B may include no arm 62 and no nozzlehead 49.

Although the substrate processing apparatus 1B discharges a nitrogen gasas the gas flows G1 and G3 to G5, at least one gas flow among the gasflows G1 and G3 to G5 may be an inert gas different from the inert gasof the other gas flows.

The substrate processing apparatus according to the third embodimentconfigured as described above restricts a rinse liquid from wrappingaround the to-be-processed surface until the rinse liquid moves from theposition PL2 to the position PL1 or its vicinity in the circumferentialdirection of the substrate W, thus restricting the dilution of thechemical solution discharged onto the position PL1 with the rinse liquidat the peripheral portion of the to-be-processed surface of thesubstrate W. The rinse liquid has wrapped around the end face from theto-be-protected surface before the rinse liquid arrives at the positionPL1 or its vicinity in the circumferential direction of the substrate W,thus washing away the chemical solution that begins to wrap around theto-be-protected surface from the position PL1 with the rinse liquid todilute the chemical solution. Thus, the to-be-protected surface can beprocessed with a chemical solution that has wrapped around theto-be-protected surface while the peripheral portion is processedefficiently by discharging the chemical solution onto the peripheralportion of the to-be-processed surface of the substrate W.

The substrate processing apparatus according to the third embodimentconfigured as described above discharges an inert gas onto theperipheral portion of the to-be-processed surface of the substrate W atthe position P3 between the positions PL2 and PL1. The inert gas flowsdownstream in the direction of rotation of the substrate W while flowingtoward the periphery of the substrate W along the to-be-processedsurface due to the rotation of the substrate W. This restricts the rinseliquid from wrapping around the to-be-processed surface while the rinseliquid that has been discharged onto the to-be-protected surface of thesubstrate W at the position PL2 moves to the position PL1 or itsvicinity in the circumferential direction of the substrate W.

The substrate processing apparatus according to the third embodimentconfigured as described above discharges an inert gas onto theperipheral portion of the to-be-protected surface of the substrate W atthe position P4. The inert gas flows downstream in the direction ofrotation of the substrate W while flowing toward the periphery of thesubstrate W along the to-be-protected surface due to the rotation of thesubstrate W. The rinse liquid discharged onto the peripheral portion ofthe to-be-protected surface at the position PL2 loops, on the substrateW in the circumferential direction of the substrate W, downstream in thedirection of rotation of the substrate W while being drained out of thesubstrate W from the periphery of the to-be-protected surface due to therotation of the substrate W. Thus, a part of the rinse liquid dischargedonto the position PL2 arrives at the position P4. The rinse liquid thathas arrived at the position P4 is thus blown off, by the inert gasdischarged onto the position P4, from the peripheral portion of theto-be-protected surface of the substrate W toward the outside of thesubstrate W, thus reducing the volume of the rinse liquid further. Thisreduces the volume of the rinse liquid that loops around the peripheralportion of the to-be-protected surface in the circumferential directionof the substrate W and again arrives at the position PL2. Consequently,a rinse liquid newly discharged onto the position PL2 is restricted fromcoming into contact with the rinse liquid that has looped around theperipheral portion to generate splashes. Also, the rinse liquid isrestricted from increasing excessively in amount to wrap around theto-be-protected region of the to-be-processed surface of the substrateW.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the recess 170 with the opening 174 opento the opposed surface S7 of the heater 71B is fanned in the heater 71B,and the opening 174 is opposed to the portion adjacent to the positionPL2 in the rotation path of the lower surface peripheral portion.Besides, at least the outlet portion of the nozzle 55 is accommodated inthe recess 170. This enables the following operations simultaneously:bringing the heater 71B closer to the to-be-protected surface of thesubstrate W to efficiently heat the peripheral portion of the substrateW from the to-be-protected surface side, and discharging the rinseliquid onto the position PL2.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the recess 170 of the heater 71B passesthrough the heater 71B vertically, thus facilitating the work ofarranging the nozzle 55 that discharges the rinse liquid.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the opening 175X open to the outerperipheral surface S10 of the heater 71B is further formed in the recess170X of the heater 71X, and the opening 174 open to the opposed surfaceS7 and the opening 175X are continuous with each other. This facilitatesthe work of arranging the nozzle 55 that discharges the rinse liquid.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the opening 175 open to the outerperipheral surface S10 of the heater 71B and the opening 176 open to thesurface S8 opposite to the opposed surface S7 are formed in the recess170 of the heater 71B, and the openings 176, 175, and 174 aresequentially continuous with each other. This facilitates the work ofarranging the rinse liquid discharge nozzle.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the gas flow G4 of the preheated inertgas is discharged into the space V1 between the opposed surface S7 ofthe heater 71B and the surface (to-be-protected surface), which isopposite to the to-be-processed surface, of the substrate W. Thisrestricts the atmosphere G9 from entering the space V1 to restrict adrop in the heating efficiency of the substrate W, and also restricts adrop in heating efficiency also by the gas flow G4 of the inert gas.Thus, the substrate W is processed while being efficiently heated.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the gas discharge mechanism 444discharges the gas flow G4 of the inert gas preheated by the heater 71B.Thus, there is no need to separately provide the heater for heating theinert gas, reducing the cost of the substrate processing apparatus.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the gas discharge mechanism 444 includesthe heating flow path 74B arranged along the heating element 73B of theheater 71B and discharges the inert gas heated by the heater 71B whenflowing through the heating flow path 74. This improves the heatingefficiency of the inert gas by the heater 71B.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the heating flow path 74B is arrangedtwo-dimensionally along the heating element 73B, thus further improvingthe heating efficiency of the inert gas by the heater 71B.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the heating flow path 74B is arrangedopposite to the substrate W relative to the heating element 73B, andthus, can efficiently heat both of the substrate W and the inert gas bythe heating element 73B.

In the substrate processing apparatus according to the third embodimentconfigured as described above, the gas discharge mechanism 444 includesthe outlets 78 and 79 respectively provided in the outer peripheralportion and the inner peripheral portion of the annular heater 71B anddischarges the inert gas through the outlets 78 and 79. This effectivelyrestricts the atmosphere G1 around the heater 71B from entering thespace V1 between the substrate W and the heater 71B. This enables thesubstrate W to be heated efficiently.

While the invention has been shown and described in detail, theforegoing description is in all aspects illustrative and notrestrictive. It is therefore understood that numerous modifications andvariations can be devised without departing from the scope of theinvention.

What is claimed is:
 1. A substrate processing apparatus comprising: asubstrate holder rotatably disposed about a predetermined rotation axisand holding a substrate substantially horizontally; a rotating mechanismthat rotates said substrate holder about said rotation axis; aprocessing liquid discharge unit that discharges a liquid flow of aprocessing liquid such that said liquid flow comes into contact with alanding position in a rotation path of a peripheral portion of an uppersurface of said substrate being rotated about said rotation axis; and agas discharge unit that discharges a first gas flow of an inert gas fromabove toward a first position upstream from said landing position in adirection of rotation of said substrate in said rotation path so as todirect said first gas flow from said first position toward a peripheryof said substrate, and discharges a second gas flow of the inert gasfrom above toward a second position upstream from said first position inthe direction of rotation of said substrate in said rotation path so asto direct said second gas flow from said second position toward theperiphery of said substrate, wherein a kinetic energy of said second gasflow when said second gas flow is discharged is lower than a kineticenergy of said first gas flow when said first gas flow is discharged. 2.The substrate processing apparatus according to claim 1, wherein a flowrate of said second gas flow when said second gas flow is discharged islower than a flow rate of said first gas flow when said first gas flowis discharged.
 3. The substrate processing apparatus according to claim1, wherein a flow speed of said second gas flow when said second gasflow is discharged is lower than a flow speed of said first gas flowwhen said first gas flow is discharged.
 4. The substrate processingapparatus according to claim 1, further comprising another gas dischargeunit that discharges the inert gas from above onto a central portion ofthe upper surface of said substrate to generate a gas flow spreadingfrom said central portion toward the periphery of said substrate.
 5. Thesubstrate processing apparatus according to claim 4, wherein a flow rateof a gas flow discharged from said another gas discharge unit when thegas flow is discharged is higher than any flow rate of the flow rate ofsaid first gas flow when said first gas flow is discharged and the flowrate of said second gas flow when said second gas flow is discharged. 6.A substrate processing apparatus comprising: a substrate holderrotatably disposed about a predetermined rotation axis and holding asubstrate substantially horizontally; a rotating mechanism that rotatessaid substrate holder about said rotation axis; a chemical solutiondischarge unit that discharges a chemical solution onto ato-be-processed surface of said substrate; a heater including an opposedsurface opposed to an opposite surface of said substrate opposite to theto-be-processed surface in a contactless manner, said heater heatingsaid substrate; and a gas discharge mechanism that discharges an inertgas preheated into a space between the opposite surface of saidsubstrate and said opposed surface of said heater.
 7. The substrateprocessing apparatus according to claim 6, wherein said gas dischargemechanism discharges said inert gas preheated by said heater into saidspace.
 8. The substrate processing apparatus according to claim 7,wherein said heater includes a heating element extending along saidopposed surface, and said gas discharge mechanism includes a heatingflow path arranged along said heating element as a flow path throughwhich said inert gas is supplied, and discharges, into said space, saidinert gas preheated by said heater when flowing through said heatingflow path.
 9. The substrate processing apparatus according to claim 8,wherein said heating flow path is two-dimensionally arranged along saidheating element.
 10. The substrate processing apparatus according toclaim 8, wherein said heating flow path is arranged opposite to saidsubstrate relative to said heating element.
 11. The substrate processingapparatus according to claim 6, wherein said heater is annularlydisposed along a peripheral portion of said substrate, and said gasdischarge mechanism includes an outlet disposed at an outer peripheralportion of said heater and an outlet disposed at an inner peripheralportion of said heater, and discharges said inert gas into said spacefrom said respective outlets.
 12. A substrate processing apparatuscomprising: a substrate holder rotatably disposed about a predeterminedrotation axis and holding a substrate substantially horizontally; arotating mechanism that rotates said substrate holder about saidrotation axis; a chemical solution discharge nozzle that discharges achemical solution such that said chemical solution comes into contactwith a first position in a first rotation path of a peripheral portionof a to-be-processed surface of said substrate; and a rinse liquiddischarge nozzle that discharges a rinse liquid such that said rinseliquid comes into contact with a second position in a second rotationpath of a peripheral portion of a to-be-protected surface of saidsubstrate opposite to the to-be-processed surface, wherein said secondposition is a position upstream from said first position in a directionof rotation of said substrate and is set in advance such that, beforesaid rinse liquid moves in a circumferential direction of said substrateand arrives at said first position or its vicinity, said rinse liquidhas wrapped around an end face of said substrate from saidto-be-protected surface of said substrate and hardly wrapped around theperipheral portion of said to-be-processed surface.
 13. The substrateprocessing apparatus according to claim 12, further comprising a gasdischarge nozzle for to-be-processed surface that discharges an inertgas such that said inert gas comes into contact with a third position insaid first rotation path, wherein said third position is located betweensaid first position and said second position along a periphery of saidsubstrate.
 14. The substrate processing apparatus according to claim 12,further comprising a gas discharge nozzle for to-be-protected surfacethat discharges an inert gas such that said inert gas comes into contactwith a fourth position in said second rotation path, wherein said fourthposition is located adjacent to said second position upstream from saidsecond position in the direction of rotation of said substrate.
 15. Thesubstrate processing apparatus according to claim 12, further comprisinga heater annularly disposed along the peripheral portion of saidto-be-protected surface of said substrate and including an opposedsurface opposed to said to-be-protected surface in a contactless manner,said heater heating the peripheral portion of said substrate, whereinsaid heater includes a recess including an opposed-surface opening, saidopposed-surface opening being opposed to a portion adjacent to saidsecond position in said second rotation path of said substrate and beingopen to said opposed surface, at least an outlet portion of said rinseliquid discharge nozzle is accommodated in said recess, and an outlet ofsaid rinse liquid discharge nozzle is disposed in said opposed-surfaceopening when said recess is viewed from said opposed-surface openingside.
 16. The substrate processing apparatus according to claim 15,wherein said recess of said heater passes through said heatervertically.
 17. The substrate processing apparatus according to claim15, wherein said recess of said heater further includes anouter-peripheral-surface opening open to an outer peripheral surface ofsaid heater, and said opposed-surface opening and saidouter-peripheral-surface opening are continuous with each other.
 18. Thesubstrate processing apparatus according to claim 16, wherein saidrecess of said heater further includes an outer-peripheral-surfaceopening open to an outer peripheral surface of said heater and anopening open to an opposite surface opposed said opposite surface, andsaid opening open to said opposite surface, saidouter-peripheral-surface opening, and said opposed-surface opening aresequentially continuous with each other.